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Immunology > Week 9- > Flashcards

Week 9- Flashcards

1
Q

When examining tool marks, what questions should be asked

A
  • Can it be identified by that class of tools? ( wanting to work out if it was a Nike size 12 made between years of 2014 and presently… thats the class) Can you match to that specific tool aka individual characterisitcs
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2
Q

What do class characteristics of tools tells us

A

Can indicate group that tool came from

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3
Q

What are some class characteristics of tool marks

A
  • Width of blade, shape of blade
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4
Q

Cons of class characterisitcs

A
  • Cannot identify to a single source
  • Tool mark may not include entire tool (e.g. tool may have been 12 inch knife but blade only inflicted 4 inch deep wound)
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5
Q

What are the individual characteristics? How are individual characteristics of tool marks made? Example?

A
  • form of pattern evidence, concerns in NAS report
  • accidental or unplanned events
  • can be formed by manufacture (when u manufacture a tool, the machines make marks that are individual to all others cause its picking up metals) or use (if you use hammer to breaks bricks, it’s going to look difference e.g.
  • E.g. mark at the end of chisel
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6
Q

How to compare tool marks?

A
  • MUST compare like to like
  • Never place suspect tool in mark
  • Take impression in soft substance (e.g. make an impression in wax)
  • Compare the tool marks under mircroscope
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7
Q

Never place suspect tool in mark, why?

A
  • If you put it in there, lawyer may say u created that mark yourself
  • Or you may end up making those marks yourself by putting them in
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8
Q

How to make an impression?

A
  • Use gradually harder materials to get impression (wax then lead etc.)
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9
Q

What happens when you can’t make the impression?

A

Then it couldn’t have been the correct tool

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10
Q

What is an comparison microscope?

A

Is a basic compound microscope attached to another basic compound microscope with a single optics

  • So you have ur sample under one, and ur other sample under the other. So when you look at it, you get a combined image of both sets of sample
  • Go from unknown to known sample
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11
Q

When examining specifically class characteristics, what should we ask

A
  • Are the marks the same?

- Can they eliminate?

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12
Q

When examining specifically individual characteristics, what should we ask

A
  • How many do we need?

- Usually 7-8 matches needed (but usually hundreds)

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13
Q

Examples of things tool mark and firearms section would examine?

A
  • tool match
  • wire match
  • pliers on lock
  • LSD pill
  • Safecracker
  • Inside cut of rubber and cast
  • Murder –cut rib
  • Murder weapon?
  • Borken bolt
  • Fatal hit and run
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14
Q

How to reduce the possibility of a false match?

A
  • more points of individual characteristics means less chance of false match
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15
Q

Is a tool was new does it still contain individual characteristics?

A

Yes

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16
Q

What is the RCMP depot test?

A

When you join the RCMP, you are provided with boots that are all exactly the same (manufacturer and type). They examined each boot and were able to tell each one apart (they had individual characteristics). This is before giving them to the trainees. Then after giving them to the recruits, who go through the same obstacles and routines. When they went off base they would wear different shoes to ensure they had the same circumstances. They checked halfway thru depot and at the end, they found that all the boots were unique.

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17
Q

What happens if the tool is re-used after the crime?

A

If the tool is changed it may provide a false match (more likely not a match at all as it has been changed)

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18
Q

What must the examiner consider when looking at tool marks

A
  • Combination of class and accidental characteristics
  • How manufactured?
  • Every different can be explained
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19
Q

How do you establish that a tool, made a specific mark?

A
  •  A significant and unique similarity must exist between the test and the suspect tool mark
  •  Class characteristics must agree
  •  Individual characteristic must agree
  •  No unexplained differences must exist.
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20
Q

How do you obliterate serial #’s?

A
  • Serial # on gun are dye stamped (a much heavy piece of much stronger metal has been pressed into it and created an impression). When it creates an impression of usually numbers and letters. You haven’t just made the impression but also damaged the metal crystals underneath. So when somebody sand away the serial #, you can’t see the #. However the area underneath is still damaged. So you can take wipe with etching acid and the damaged bit gets destroyed and melts away, so now your serial number comes back.

Disadvantage: Might have sand it away all of it deeper. Or now we often don’t dye stamp it but laser etched it.

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21
Q

What is firearms examination

A

Specialized form of tool mark examination

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22
Q

What is barrel

A

a tool that marks the bullet, breech face.

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23
Q

What is barrel

A

Is a tool that marks the bullet and marks the soft lead and marks the parts of the cartiledge

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24
Q

What other tools are examined in firearms

A

Firing pin, chamber, if automatic has an extractor as well. All of these are tools aka cause damage to the bullet and leave a mark on it, giving it individual characteristics

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25
Q

What is a projectile?

A
  • A bullet or “slug”
  • Usually made of lead
  • May have jacket (full metal jacket bullet) which prevents fragmenting
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26
Q

How to make a gun barrel? Importance of gun barrel for firearm examination?

A
  • Use a broach, which hollows out solid bar of steel, to make barrel
  • This process leaves small scratches when making barrels. As it does each one, picks up dirt, loses dirt etc. So, each barrel is unique
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27
Q

What is rifling

A

After barrel is drilled, rifling (spiral grooves) is added. This is done so to put a spin on bullets, prevents tumbling. It also adds more marks on bullets, giving more class and individual characteristics. The number of grooves and the direction (clockwise or anticlockwise) differs by each manufacturer, giving the class characteristics

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28
Q

What are grooves and lands?

A

In rifling, the Lands is the original diameter of the barrel, and when you put in grooves it digs deeper. When you fire bullet, grooves and Lands reverse on bullet

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29
Q

When comparing bullets and guns, what steps?

A
  • Must compare like with like
  • Is gun safe to fire? Don’t want it exploding in lab
  • Do NOT clean it because you’re changing things
  • Test bullet fired into water because it won’t deform it
  • Test bullet compared with suspect bullet
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30
Q

When examining bullets and guns, what would you look at to assess class and individual characteristics ?

A 
Look for class first to see if they match, if do continue onto individual:
- Class characteristics: Same # of lands and grooves on bullet and gun? Same direction (clockwise and anticlockwise)? Caliber of bullet (original width of barrel b4 rifling, measures land to land) ?
  • Accidental (Individual) characteristics: Use? Manufacture?
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31
Q

Why do we often find the cartilage at the scene

A
  • Its super hot so they drop they

- They’re shot far away

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32
Q

How can different tools produce the same mark?

A
  • Machining carryovers to next tool in manufacturer
  • Class may be mistaken for accidental (like if made in different country diff protocol)
  • Random arrangement
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33
Q

How can the same tool produce different marks?

A
  •  Metallic deposits cleaned away (either by motion of bullet or person cleaning)
  •  Rust/Corrosion
  •  Too much lubrication (bullet will slide)
  •  Different hardness of materials used on (If using a diff kind of slug can get diff patterns forming)
  •  Tool broken in use, ground down
  •  Bullet too small (instead of going smoothly it touches different areas)
  •  Chambers misaligned – shearing
  •  Erosion due to too high velocity bullet
  •  Extensive Use (go to gun range shoot off several rounds will change it slightly)
  •  Deliberate altering (Ted Bundy did this)
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34
Q

How can cartridges tell a story?

A

Ejector is shooting out empty cartridges and you can trace where the cartridges land as to where the shooters position is each shoot

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35
Q

Use of gun shot residue?

A
  •  Can determine position of antagonists
  •  Distance apart
  •  Ammunition propelled by expanding gases (In ideal situation all gun powder burns up but in reality you get burned, partially burned and unburned powder)
  • In order to do this, MUST have suspect weapon AND suspect ammunition (different weapon or different ammunition will create very different patterns)
  •  Fire into similar material at different distances when trying to replicate the gun shoe residue
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36
Q

What are characteristics of a contact/close wound?

A
  •  Unburned powder inside wound
  •  Stellate (starshaped pattern) tearing (of skin and possible bone)
  • Quite a clean wound outside, most damage is seen inside
  •  Bullet wound surrounded by rim of vaporous lead
  •  Fibres of clothing may be melted
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37
Q

What wound is made if shot between 30-45 cm (12-18) inches?

A
  •  Halo of vaporous lead around wound

-  Unburned powder around wound

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38
Q

What wound is made if shot between 30-61 cm (12-24) inches?

A

- Only soot deposited on wound (no stellate patterning)

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39
Q

What wound is made if shot between 64-91cm (25-36 inches)?

A
  •  Scattered specks of unburned and partially burned gunpowder grains
  •  Stippling under skin
  •  No soot or blackening, or vaporous lead on tissue itself
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40
Q

What wound is made if shot greater than 91 cm (3 feet)

A
  •  No residue on target

-  Bullet wipe – on edge of wound – wiped off bullet as it entered flesh

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41
Q

Why do we have to know the gun and ammunition to get right match, and can only make general conclusions?

A
  • Diff guns firing same bullet show different results
  • Same bullet with diff guns show different results
  • A silencer also changes result
  • If the bullet was fired through something like a curtain will change the result as well
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42
Q

How can we test if the suspect shot the weapon (early tests and modern day tests)? Cons of each

A

Early tests – Dermal Nitrate Test:
- Test for gunpowder cause gunpowder has nitrates
Cons: Nitrate is also in urine, cosmetics, tobacco
- Very easily get  false positives
- May just have been standing nearby
- Easily washed off

Now test for Primer Residue

  •  Lead styphnate, barium nitrate & antimony sulfide (don’t need to know)
  •  Specific, only found in primer
  •  May be transferred by handling – look at amount and where it is to make conclusions
  •  Still easily washed off
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43
Q

Why is a bullet wound so much worse than knife wound?

A

Because of incredible velocity that a bullet brings with it. A knife velocity is only how fast the man or women can give. But bullets come with tremendous velocity and comes with 2 kinds of cavities, temporary and permanent cavities. Temporary cavity created is extremely deadly

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44
Q

What is temporary cavity?

A
  •  Massive stretching due to gases expanding

-  Briefly, very massive wound, much bigger than projectile

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45
Q

What is permanent cavity?

A

- Actual damage to tissue

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46
Q

Variables that we need to know in order to make a match?

A
  • If do not have weapon or ammunition, can only make general conclusions
  • If used silencer
  • If bullet was fired through something
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47
Q

What do bullets with hollow points do on contact?

A
  • Mushrooms on contact
  • Creates large wound
  • Lots of stopping power
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48
Q

Characteristics of civilian ammunition

A
  • NO full metal jacket

- Mushrooms and fragments, great stopping power (for hunting)

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49
Q

Characteristics of military ammunition

A
  • Full metal jacket
  • Injure instead of kill (if you injure them, people will try to treat them and takes manpower off the field)
  • Doesn’t mushroom or fragment
  • Stopping power not as good
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50
Q

What material does forensic biology cover

A
  • Any biological material such as blood, semen, saliva, hair, tissue etc.
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51
Q

First question asked by forensic biologist

A
  • Is it human?

- Can it be individualized (find out who that human being actually is)?

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52
Q

How has forensic biology changed over time

A
  • In past, mostly class evidence

- Now, with DNA, material can be individualized

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53
Q

Training needed for forensic biologists

A
  •  Civilian Scientists or Civilian members of RCMP
  •  Minimum of B.Sc. in biology, molecular biology, biochemistry, chemistry ( 3 year Diploma OK for basic work)
  • Start off as technician in Evidence Recovery Section
  • Then go through training period to become a PCR Analyst (3-5 yrs. in this)
  • Then become specialist who give expert testimony
  •  Biology Reporting officer does the statistics/probability
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54
Q

What does the Evidence Recovery Section do

A

- Search Technologists
- Locate and isolate and recover anything forensically important evidence e.g. -
 Blood
 Semen
- Presumptive tests
– Entry level position but very important/Frontline

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55
Q

Hair characteristics?

A

Hair itself (without DNA) primarily provides class characteristics, cannot individualize (however very important to eliminate):

  •  Shed everywhere
  •  Shed all the time
  • Made up of three different areas: Cuticle, Cortex, and Medulla

Cuticle (outer covering)

  •  Resistant to desiccation – keratinized (so lasts for long time)
  • Made up of overlapping scales. The scale pattern is different by species (human vs. animal)

Cortex

  •  Under cuticle, it holds the pigment granules
  • Pigment granules have diff colour, shape, and distribution. Help to differentiate between two people

Medulla

  •  Canal in centre
  •  Medullary index can be calculated. - It is much wider in animals than humans
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56
Q

How do we ID species? Is it human or animal?

A
  • Scale pattern in cuticle: Take a microscope slide, take clear nail polish, and put it on the slide. Put air in it, and let polish dries. Now you made a cast of hair.
  • If animal still may be related to scene (pet dog of offender)
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57
Q

What does the examiner doing during hair examination

A 
Once identified is human (thin medulla, smooth cuticle) look at:
Where is hair from on body?
- Beard – triangular in X-section
- Scalp, pubic – oval
- Pubic – highly twisted

Ancestry of hair?

  •  Negroid – flat, oval in X-section, very curled, dense uneven pigment
  •  Mongoloid – wide in X-section, coarse pigment
  •  Caucasoid - oval-round in X section, fine to coarse pigment evenly distributed

If have treated hair (can look at where it stopped and where it started since we know how long it takes hair to grow). It also breaks easily

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58
Q

Examination of base of hair will tell if hair is forcibly removed or shed naturally. Can tell if it was pulled out during fight or aggression.

A
  • Hair forcibly removed has root still attached and will provide DNA
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59
Q

In order to do hair comparison what must you do

A
  • There are about 20+ factors to compare
  •  Need a comparison sample – compare unknown hair at scene with suspect and victim
  •  Adequate sample required (from victim) – RCMP recommends:
    •  80-100 PULLED scalp hairs
    •  30-50 PULLED pubic hairs
    •  From all over region (like all over public region just not one)
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60
Q

What are the possible results of hair examination?

A

Positive – consistent with donor

-  Consistent with that person
- However could be a coincidental match (say consistent with, never a match)

Negative – not consistent with donor

  •  Did NOT come from that person
  • Or known sample was not representative, or contained too few hairs
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61
Q

Is hair evidence class or individual evidence

A
  • Not usually individualizing – corroborative evidence (to other class evidence)
  • Only individualizing if hair root (has DNA)
  •  Hair shaft has mtDNA, maternal line only eg. Caylee Anthony case, root banding
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62
Q

Concerns with hair evidence?

A
  • Presumptive evidence (aka class evidence) only unless corroborated with DNA
    - FBI Analysis that looked at past cases and did DNA (either nuclear or mtDNA)
    -> 1996-2000 - 11% wrong!
     -> 95% of cases, FBI examiners overstated matches (said its a match instead of consistent with him and 5% of the population)
    -> 32 death sentences (14 dead)
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63
Q

What victim is assaulted what is used?

A

Sexual assault kit
- Need samples from victim AND suspect
- If victim is alive performed by medical personnel – forensic nurse aka the SANE (sexual assault nurse examiner)
- If victim is deceased – pathologist
- Check for semen by swabs from vagina, cervix, rectum, anus and mouth
-> External area
-> Allowed to dry (prevents mold
- Pubic combinng
-> Possibly hair from attacker was left
 ->Need control sample from victim
- Fingernail scrapings (if dead, bag hands)
- This entire process is unpleasant so victim must consent
- If unconscious, victim must wake up first, thus evidence may be lost
- Bill C-104: allowed police to take evidence by force is necessary from victim
- Suspect – need all samples

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64
Q

What are characteristics of presumptive and confirmatory tests

A

Do presumptive tests first. Then confirmatory if necessary

  •  Presumptive tests
    • >  Might be suspected substance
    • >  False positives
    • >  OR is definitely NOT suspected substance 
  • Confirmatory tests 
    • > Definitely is the suspected substance
    • > NO false positives
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65
Q

How to test for blood evidence

A
  •  If on person, swabs as before
  • If on item, swab but be careful in case of other evidence
  • If on clothes or weapons, place in dry paper bag 
  • At scene? Cut wall out
  •  Visible? swab or collect item
  •  Not visible? Do presumptive colour tests
  •  Colour tests by chemical + alternate light source
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66
Q

What are the possible presumptive tests for blood?

A
  •  Kastle Meyer/Phenolphthalein: turns bright pink
  • >  False +ve with horseradish, potato
  •  Haemastix test: turns green
  • >  False +ve with e.g. rust, bleach
  • >  Interferes with DNA extraction
  •  Luminol  Darkness/alternate light source, turns blue glow
  • >  False +ve with iron, copper, bleach, horseradish
  •  Bluestar, requires not complete darkness
  •  False +ve with detergents, bleach, iron, thyme
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67
Q

Haemastix test problem?

A

–

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68
Q

Presumtive tests for blood?

A
  •  If positive – might be blood 
  • Needs to be confirmed
  •  If negative – definitely NOT blood, which is very useful
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69
Q

Concerns for presumptive tests for blood

A
  •  Presumptive test only! Might be blood, but false positives possible
  •  Must do confirmatory test
  •  Dingo baby/Lindy Chamberlain case, Australia, 1980
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70
Q

Confirmatory test for blood? Con of this test?

A
  •  Haemachromagen test
  •  No false positives
  •  Only shows it is blood, not whether human or animal
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71
Q

How to determine if blood is human?

A
  •  Precipitin test (old way… take human blood and inject it in rabbit. The rabbit produces anti-sera to it. Can use blood from rabbit and put into vial, add suspect substance, if human blood, anti-sera will precipitate)
  •  Commercial anti-sera kits available now
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72
Q

How to identify a person through blood

A
  •  Ol way was through blood typing
  • Now we have the ABO system, MN system, rhesus system– class characteristics
  •  DNA – 1985 – individual characteristics
  • After DNA, previous Serology section now called  Forensic Biology Section
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73
Q

What are presumptive tests for semen

A
  •  Fast Blue test (Acid phosphatase colour test)
  •  Acid phosphatase is produced from prostate gland – 400X more common in semen than other fluids (but still found in other fluids so still presumptive test)
  •  Sodium alpha napthylphosphate and fast blue B dye
  •  Rapid positive result (turn blue) = semen
  •  Vasectomized males – still positive cause testing for semen not sperm
  •  Run piece of moist filter paper over large area like carpet (if doesn’t come up blue or really slowly prob false positive)
  •  False positives with e.g. fungi, contraceptive creams – slower to react
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74
Q

Confirmatory test for semen?

A
  •  Spermatozoa ONLY confirmatory test
  •  IN PAST: PSA or p30 test (Prostate Specific Antigen) was considered to be confirmatory
    - > Was believed to be only in semen
    - > BUT now found in breast milk, amniotic fluid, female urine – but low levels
    - > Recently found in vaginal fluids as same level as males!
    - > No longer used as confirmatory in Canada
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75
Q

How to individualize males

A
  • If sperm is present, we have his DNA
  •  Vasectomy - no sperm
    - > Can man be identified?  Is sperm the only DNA in sample? No, epithelial (skin) cells rubbed off during intercourse have DNA
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76
Q

Possible reasons for why when rape is suspected, but there no semen

A
  1. No ejaculation
  2. Condom
  3. Victim washed
  4. Offender has disease that affects semen
  5. Victim has vaginal conditions that destroy semen
  6. Bad collection
  7. Victim lied or mistaken
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77
Q

In all rape cases, time is a vital factor. When must everything be swabbed by?

A

- Vaginal sample
-> Motile sperm – 8 h
-> Non-motile sperm - 16 h
-> Just sperm heads: <48h
- Oral sample
-> Up to 6 h (rare cause continuously swallowing)
- Anal and rectal samples
-> Up to 20 h
- All swabs will be taken

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78
Q

Other body materials

A
  •  Saliva (bite marks?) – skin cells
  •  Feces –rubbing motion gives skin cells
  •  Urine? if infection – white blood cells
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79
Q

DNA

A
  •  Made up of chain of pairs of nucleotides
  •  Double helix
  •  Sections of DNA “code” for a chemical product
  •  Coding sections = genes
  •  One molecule of DNA = many genes
  •  DNA molecule – compact –cell nucleus
  •  Chromosome
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80
Q

Chromosomes and reproduction

A
  •  Humans have 23 pairs of chromosomes (46 total)
  •  All come in pairs
  •  22 regular or autosomal pairs
  •  1 pair of sex chromosomes X, Y, Everyone has 2 chr.1’s, 2 chr.2’s, 2 chr.3’s etc. (sex is entirely determined by male)
  •  Chromosomes – strings of genes, all in pairs
  •  Both chromosomes in a pair have same genes
    - > May have different versions or alleles
    - > e.g. gene for eye colour is on middle of chr. 15
    - > Both members of pair of chr. 15 have eye colour gene in same place.
    - > Alleles could be blue, green, brown, violet
  •  Each person only has 2 - so 2 blue, or 2 brown, or 1 brown and 1 green etc.
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81
Q

Egg (23) + sperm (23) = 46

A
  •  Meiosis – doubles the chromosome material in testes and ovaries so briefly
  •  Then SHUFFLES the genes between the 4
  •  Then reduces chromosome # to 23 in each sperm or egg
  •  Each sperm or egg is unique
  •  Unique egg + unique sperm = 1 unique complete cell
  •  Divides into 2, then 4, 8, 16 etc. = 1 baby
  •  All cells in human body the same
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82
Q

99% of human DNA is identical

A
  •  Most functions identical in everyone e.g.
    - > Eyes function the same way
    - > Stomach digests in same way
    - > Structure of skin identical
  •  Only 1% different
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83
Q

DNA typing

A

- In between the genes – ‘junk’ DNA
- Short Tandem repeats (STR’s)
- Repetition of sequences of DNA
- Don’t know what they do, but VERY VARIABLE between people
- In world - numerous possibilities for number of times a particular sequence of base letters
can repeat themselves on a DNA strand
- Even higher when look at 2 places on chromosome, or 3 etc.
- Look at areas in chromosomes which are known to be very variable

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84
Q

RFLP

A
  •  Restriction Fragment Length Polymorphisms
  •  Old technique
    - > Needed good quality DNA, not degraded like in deceased
    - > Large amounts of blood needed
    - > 6-8 weeks
    - > Expensive
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85
Q

PCR

A
  •  Polymerase Chain Reaction
  •  Makes many copies of original
    - >Works on degraded DNA
    - > Tiny amount of blood needed
    - > Fast
    - > Inexpensive ~25c/sample
    - > Easily stored in database
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86
Q

High profile cases

A
  •  Gail Miller – killed before DNA fingerprinting available
  •  Christine Jessop – only RFLP available, too degraded
  •  In both cases innocent men wrongly convicted
  •  Later re-examination of degraded DNA with PCR
  •  Exonerated David Milgaard & Guy Paul Morin
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87
Q

Contamination?

A

Con of PCR is possibility of contamination (just breathing on sample can destroy it)

  •  May magnify wrong piece of DNA
  •  Scene security to prevent contamination:
    - > Bunny suits
    - > Double gloves
    - > Masks
  •  Separate teams for related scenes
    - > Lab security
    - > Separate labs for each scene
    - > Separate scientists for each scene
    - > Double blind test often done
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88
Q

STRs (Short Tandem Repeats)

A
  •  Loci (or “addresses”) on chromosome known to have short sequences of nucleotides which repeat – very variable between people
  •  Get frequency – chance of someone else having same profile
  •  Several loci analyzed
  •  Multiply frequency
  •  Multiplexing – several STRs at once – 15 today
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89
Q

When case enters lab…

A
  1. Stains identified
  2. Cut out
  3. Extract and purify DNA
  4. PCR
  5. Analyze results from scene, controls from victim, known from suspect (all done separately,
    in different rooms by different scientists)
  6. Determine statistical significance – based on population databases
  7. Prepare report
  8. Independent File Review
    -> Some of original stain kept for opposing counsel
    -> Double-blind studies to check accuracy
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90
Q

Probabilities

A
  •  e.g. 1 in 8 billion
  •  Not probability of guilt!
  •  Does not mean it IS his DNA
  •  Means that probability that it came from someone else is very low
  •  Affected by relatedness
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91
Q

CODIS

A
  • COmbined DNA Index System
  • Convicted Offender Index (COI)
    - > Profiles of offenders convicted of designated offenders (if primary up to defines why you shouldn’t, if secondary up to prosecution why u should)
  • Crime Scene Index (CSI)
    - > Profiles of unknowns from crime scenes
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92
Q

DNA, still just a tool!

A
  •  Exonerations!
  •  US - estimated that 30% of those convicted before DNA, will be exonerated by DNA
  •  Does not prove guilt
  •  Just says ‘he was there’
  •  Concern with faulty analyses
  •  Planted evidence?
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93
Q

DNA and mtDNA

A

- The “other” DNA aka Mitochondrial DNA (mtDNA)

  • Nuclear DNA
    - > In nucleus, in nearly every cell
    - > From both parents
    - > Unique
  • mtDNA
    - > Many copies in each cell, in mitochondria
    - > From Mother only
    - > Same as mother
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94
Q

Nuclear DNA (the regular stuff)

A
  • Half from mother, half from father
  • Equal amounts of DNA from each parent
  • But NOT equal amounts of everything else!!!
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95
Q

Contributions to next generation

A
  • Egg is 195,000 X bigger than sperm!
  • Sperm brings DNA
  • Egg brings DNA – and EVERYTHING else needed for life! – all cell contents – including mitochondria
96
Q

MtDNA

A
  •  Mitochondria – powerhouses of the cell
  •  Have their own DNA, unique from cell
  •  All mitochondria in a person come from first mitochondria in zygote – from mother
  •  No shuffling
  •  So all mtDNA in a person are IDENTICAL to their mother, brothers and sisters, grandmother, etc.
  • Same throughout maternal line
  • Can identify to that family group
  • Found in hair shaft
  • Easier to recover from very old sources (degraded)
  • Not performed forensically in Canada
97
Q

Identify victims

A
  • Closed population e.g. plane crash
  • War crimes in Argentina, large #’s of people “disappeared”
  • Grandchildren linked back to grandparents through mtDNA

Romanov Family?

98
Q

What is a questioned document

A

Any object which contains signs, symbols or marks either visible, partially visible or invisible, which convey a meaning to someone

99
Q

What does examination of questioned documents include

A
  • Handwriting and handprinting comparisons
  •  Examination of means, media and materials used to produce a document
  •  Documents that have been altered
100
Q

Training required for questioned documents?

A
  • Before accepted :
    - > B.Sc. Science (e.g. chemistry, math, biology, physics)
    - > Word blindness and dexterity tests
  • Must be civilian
  • Two and a half years of understudy (longest in lab) caused based mostly on experience
  • Continuing education
  • Certification by American Board of Forensic Document Examiners (ABFDE)
101
Q

Is graphology the same as questioned documents examination

A
  • Graphology is NOT QD
  • Graphology is determining personality from handwriting
  • Similar to reading palms and fortune telling
  • No science!
  • Caution in court
102
Q

HANDWRITING AND HANDPRINTING EXAMINATIONS

When is handwriting unique?

A
  • Majority of job
  • Handwriting is unique if:
    - > Reasonable amount of writing
    - > Executed freely and fluently
103
Q

How is handwriting developed during childhood and adulthood?

A

Child

  • > Copies alphabet, teacher, book, parent
  • > Repetition – very careful
  • > Whole words, then sentences
  • > Focus shifts from the act of writing to contents of writing

Adult

  • > Writing is a semi-conscious habit
  • > Habits very hard to change or disguise
104
Q

What are the class characteristics of hand writing?

A
  • > Copy book – all letters the same, so children all learn from same style
  • > All children from one Grade 1 teacher will learn their style
  • > Variations between countries
  • > Professional class characteristics
  • > Teenage girls in N. Am. – bubble writing
  • > Vision impaired?
105
Q

What are the individual characteristics of hand writing?

A
  •  Every person has an individual perception of different images (see things differently)
  •  Each person has individual physical makeup – dexterity
  •  Uncorrected errors become habit
  •  Child incorporates writing features from people of influence in their lives

Combined, the above make handwriting unique

106
Q

What is natural variation

A
  • Usual and normal deviations that occur within repeated specimens of a person’s handwriting (aka we all write differently everything we write smtg)
  • E.g. signature – no two ever the same
  • If signatures identical - fraud
107
Q

What is science of handwriting based on? What must you have to do the comparison?

A
  • Science based on COMPARISON (comparing unknown document to known sample)
  • Must have original document AND examples of suspect’s handwriting – called comparison samples
108
Q

Comparison samples

A
  •  Collected – collected from normal writing during everyday life
    - > Shopping lists
    - > Letters,
    - > Diaries
    - > Cancelled cheques
  •  Requested (when suspect taken into station and made to write)
    - > Obtained under warrant
    - > At police station, under police supervision

Ideally want a mix of both

109
Q

Advantages and disadvantages of collected samples?

A

Advantages

  • Naturally written, unlikely to be disguised
  • Includes broad range of natural variation
  • Time of writing can be duplicated

Disadvantages

  • Difficult to prove authorship
  • Unlikely to contain same text as QD
110
Q

Advantages and disadvantages of collected samples?

A

Advantages

  • Authorship not in dispute, witnessed
  • QD text can be duplicated
  • Quality and style can be duplicated

Disadvantages

  • Writer may try to disguise writing
  • Restricted range of natural variation
  • May not be natural – nervousness
  • Writing may not be contemporary (might be written now, but original sample was written long time ago)
111
Q

How would you obtain a requested sample to make it as reliable as possible (11)

A
  • Dictate it – read rapidly, adjusting speed so they cannot think and disguise it
  •  Do not include punctuation
  •  Must not see original
  •  Seated comfortably (or as for QD)
  •  Duplicate writing instrument and material
  •  Repeat text: para X3, signature X15
  • Remove each specimen after written
  •  Text must include all words, numbers of QD
  •  Duplicate size of QD (if it was a cheque, make it write in cheque sized things)
  •  Duplicate style of QD – e.g. letter
  •  If printed, ensure upper and lower case both used
112
Q

What is the Canada letter? Purpose?

A
  • May not want suspect to know contents of QD
  • Use Canada letter (fantasy letter)
  • Set letter – changed for each case to include all words, letters and numbers of QD
113
Q

What is needed in order to make comparison? What is looked it?

A
  •  Requires original QD
  •  Class Characteristics
  •  Individual Characteristics
  •  slope of letters, angularity, proportions, speed of the writing, the pen pressure at different points in a letter, which letters are joined and which are not, pen stops, or lifts, pen gooping, word spacing, relative dimensions of letters, connections between letters, pen movement, writing skill and finger dexterity
114
Q

How to prove authorship?

A
  • By admission
  • If witnessed
  • Identification by someone familiar with writing
  • Any means court deems acceptable
115
Q

Once analysis is done, what results can come up?

A

Positive identification:

  • Sample and QD written by same person
  • Can say strong probability or weak probability somebody wrote it

Can neither identify nor eliminate (usually cause not enough of sample)

Negative:

  • Prove that someone else wrote document
  • Writing quality is better than that which suspect is capable
116
Q

Factors which affect hand writing comparisons?

A
  • Must compare like to like e.g. hand writing to hand writing, printing to printing
  • Contemporary – writing changes over time
117
Q

Outside Influences on hand writing?

A
  • Drugs or alcohol (supposedly extends ur range)
  • Extreme emotion (fear, anxiety etc.)
  • Type of writing instrument and surface (pad or paper or directly on hard surface)
  • Writing position (pencil vs. ink)
  • Illness, physical challenge (arthritis)
118
Q

Other countries

A
  • Examiner must be familiar with class and individual characteristics of other countries
  • Must not confuse unusual class characteristics from another country with individual characteristics
  • Cannot identify writer without being able to read language
119
Q

What is disguise in QD?

A

Attempt to change own handwriting habits to avoid detection

120
Q

Characteristics of disguised writing

A
  • Simple
  •  Not fluent
  •  Change is rarely consistent
  •  Altered letter design
  •  Internal consistency disrupted
  •  Never original – several basic types
  •  Lapses back into own style
  •  Certain features never disguised
121
Q

What is simulation in QD?

A

Attempt to emulate handwriting habits of someone else (signing will of someone else)

122
Q

Characteristics of simulation writing (6)

A
  • Poorer than original
  •  Misinterpretation of strokes
  •  Heavy pen pressure
  •  Irregular pen movements
  •  Touch-ups
  •  Inaccurate ratios and proportions of letters
123
Q

Concerns/future directions

A

Daubert v. Merrill Dow Pharmaceutical Inc, 113 S. Ct. 2786 (1993)

  • During this case, QD was decided to be not a science
  • New research to prove QD is a science… developed computerization identification of mail

Computerized identification of mail (9/11)
- Anthrax

124
Q

MEANS, MEDIA AND MATERIALS USED TO CREATE DOCUMENTS?

A

Typewriters, photocopiers, computer printers, rubber stamps, graphic arts used to make currency, lotto tickets etc.

125
Q

Characteristics (class, innate, individual)

A

Class characteristics
- make and model of machine e.g. font size, design, pitch, shape

Innate characteristics
- characteristic which is common to a group, but not all in group e.g. dirt in mould for a key for manufacture of 10 printers, so only 10 have them (not individualizing but better than class)

Individual characteristics
- actual machine e.g. Damage to a key

126
Q

Photocopiers

A
  • They copy documents, and from document can get make and model of machine
  • Actual machine identified by trash marks, picker marks, damage
  • New models – leave identifying mark
  • # of copies since QD
  • If you try to photocopy currency, the photocopy will shut down and possibly call police
127
Q

Typewriters

A
  • Old ribbons – could read writing directly

- Newer ribbons – moves up and down, can still be read

128
Q

ALTERATION OF DOCUMENTS AFTER THEIR PRODUCTION

A
  • Torn paper/foil/plastic
  • Water soaked documents
  • Charred documents – IR, UV light, burn more and the writing comes back
  • Altered/erased – IR, UV light, white-out, computer
  • Latent impressions (if write on smtg leave impression on paper below it)
129
Q

What is forensic chemistry?

A
  •  Science of the everyday
  •  Study of NON-BIOLOGICAL trace evidence
  •  Heavily based on Locard’s Exchange Principle (it is the stuff we pick up and leave behind)
  •  E.g. paint, glass, fibres, drywall, glue, cleaner fluid, adhesive tape etc.
  •  Crime scene? Occurs between ordinary people in ordinary places
  •  E.g. criminal in woolly sweater leaving behind fibres from sweater, victim’s makeup may be on suspect, duct tape, bomb, materials
130
Q

What do forensic chemists analyze

A

- Anything that is not a body fluid
- Used to be part of hair and fibre section (still is in US).
- Now in Canada:
 Fibre – chemistry
 Hair - biology

131
Q

Qualifications necessary to become forensic chemist

A
  •  B.Sc. (minimum)
  •  Chemistry – lots!
  •  Able to do all basic analytical techniques
  •  Civilians (do not go crime scene)
  •  Then basic training in lab under a mentor ~ 15-18 months
  •  Mock trial
132
Q

Type of crimes involving forensic chemistry

A
  •  B & E
  •  Hit and run
  •  Arson
  •  Bombings
  • Terrorism
  •  Examine the trace evidence
133
Q

For crimes involving forensic chemistry, what is left behind in the scenes

A

B & E:

  •  Broken glass,
  •  Fragments of drywall

 Hit and run

  •  Car light glass
  •  Car lights
  •  Paint

 Safe cracking
- Packing material from safe

134
Q

In the crimes what specialists are involved? Example using home invasion

A

 E.G. Home invasion

  •  Ident (the REAL CSI!) at scene
  •  Pathologist looking at the body
  •  Biology – looking at DNA, semen
  •  Firearms – looking at spent cartridges
  •  Chemist – involved in all aspects!
135
Q

Examples of aspects that the chemist analyze

A
  •  Fibres left behind
  •  Soil from assailant’s shoes
  •  Glass on suspects clothes
  •  Rope used to tie homeowners
  •  Strange stain on floor (gasoline?)
136
Q

Chemist are very involved in arson and terrorism. What questions do they answer

A
  •  What accelerant?
  •  Where fire started?
  •  Was a timer used?
  •  What type of bomb?
  •  Made with what?
  •  Type of explosive?
  •  How was it made?
  •  Can the material be traced?
137
Q

Analysis

A

- Substance could be anything!
- Broad range of tests to determine constituents (both presumptive and confirmatory)
-> First tests (e.g. show its gasoline)
-> Further tests (shows type of gasoline – Esso)
-> Further tests (shows batch of Esso gas, which gas station it was delivered to)
First do:
- Qualitative analysis – what substances are present
Then:
- Quantitative analysis - % of each substance

138
Q

Techniques of analysis

A
  •  Basic chemistry techniques
  •  Chromatography
  •  Electrophoresis
  •  Spectrophotometry
139
Q

Chromatography

A
  •  Separates substance into components (so purifies them)
  •  Gas Chromatography – separates based on distribution between liquid and gas phase
  •  Gas chromatograph (GC) - inject sample
  •  Pyrolysis – adds heat, e.g. paint chip-gas
  •  High-Performance Liquid Chromatography (HPLC)
  •  Thin-layer Chromatography (TLC)
140
Q

What is electrophoresis

A

Separates substances on basis of electrical potential

141
Q

Spectrophotometry

A
  •  Different substances absorb light in different ways
  •  Used to identify
  •  Mass Spectrometry (MS)
  •  Gas chromatography gives preliminary tentative ID
  •  GC +MS (GC/MS) – positive ID
  •  Very basic techniques, first year chemistry
142
Q

What separates a basic chemist from a forensic chemist?

A
  • Identifying substance - basic chemistry
  •  Significance of substance – FORENSIC chemistry
  • Its all class evidence
  •  In order to have value - must determine significance
  •  May have 0 significance
  •  May be very significant
143
Q

Report and Testimony must include what

A
  • Must make significance (or lack of significance) clear in report and testimony
  •  Even a complete MATCH may have NO significance
  •  Guy Paul Morin Case (new expert witness testifying and overemphasized and said it was a match to Guy Paul Morin)
  •  Must give a significance level
144
Q

Significance

A
  • Class evidence – may be high or low significance
  •  Exact match? But may be very common – so exact match to many different items
  •  If rare – more significant
  •  How common is evidence?
  •  Need databases for comparison
145
Q

Determining Significance 1.

A
  • How common is this evidence?
  •  Develop database and find out parent population
  •  E.g. B & E, glass at scene
  •  Suspect has glass on him
    • >  Physical properties – do they match?
    • >  How common is that sort of glass?
    • >  If common, does it mean anything?
  •  Glass on person?
  •  Develop a database
  •  How common is it for regular people to have glass on them?
    • >  Get a sample of people
    • >  See how much glass on them
    • >  Shoes - ~30%
    • >  Clothes ~<2%
146
Q

So

A
  • Glass itself is common
    - But rare to have glass on clothing
    - So, significant that suspect had matching glass on clothing
     <2% population have any glass
    - Even more significant that it is that type of glass
    - Less significant if just on shoes (position on shoes?)
147
Q

Determining Significance 2.

A

- How valid is your database?
- Does it fit this person – or how likely is it that this person could innocently have this
evidence?
- Glass on clothing rare – but what if guy is a glazer?
- Suspect must fit in research population

148
Q

Validity

A
  • Found drywall on suspect?
    • >  Rare in average population
    • >  Not in person renovating
  •  Gun residue?
    • >  Rare in average population
    • >  Not in person at gun range
  •  Therefore, need database into which suspect fits
  •  How common is it to find glass on glazier’s clothes?
149
Q

Determining Significance 3

A

- What is population/situation?
- Some things may be very common in some situations and very rare in others
- Livingston in Africa
 Scenario? Identified cause white man in africa wearing white mans clothing and broke his arm previously. Never would’ve identified him if living in London
- Manure from bomb?

150
Q

Determining Significance 4

A 
- More than one type of class evidence
- Cumulative - the more there is the more significant – multiplies probabilities
151
Q

Fibres

A
  •  Natural fibres – animal or plant sources
  •  Manmade fibers
  •  Polymers –
    • >  e.g. nylon (large number of atoms)
    • >  Also include paint, adhesives, plastics
152
Q

Fibre examination

A
  •  Colour
  •  Striations on fibre
  •  Cross-sectional shape
  •  Refractive index
  •  Infrared spectrophotometry
  •  Etc.
  •  How rare is the fibre? Circumstances?
153
Q

Significance/circumstances

A
  •  Hit and Run
  •  Fuzzy sweater fibres
  •  Very common
  •  BUT – not common stuck in broken head light glass of a car with a smashed fender
  •  Glass from light on victim?
  •  Exchange of evidence – very significant
154
Q

Paint

A
  •  Everywhere!
  •  Cars – all have at least 4 layers normally
  •  Match to database of car colours
  •  Chemically examine paint – e.g. chromatography
  •  If repaint job – more significant but harder to find
  •  Car brake lights – on or off?
155
Q

Arson

A
  • Chemist may attend, more likely special fire investigators
    - Fire Investigators –usually ex fire fighters
    -> May be direct arson for the sake of the fire
     -> May be insurance
     -> May be to disguise a crime
    - Very difficult to destroy a body!
    - Usually lots of evidence left behind!
    - Remember – body in dumpster?
156
Q

Arson?

A 
- Was it arson?
-  Accelerant?
     -> Gas? 
     -> Chemicals?
     ->Kindling? 
     -> Bounce?
- Significance?
      -> Where is it found?
157
Q

Samples

A
  •  Collect Sample
  •  Must take a control
  •  If an accelerant is found, is it also on control?
  •  Then maybe not used as an accelerant
  •  Many accelerants can be specifically identified (to a particular gas station)
158
Q

Explosions, bombs

A
  •  Usually homemade
  •  How was it constructed?
  •  What was it made of?
  •  What explosive was used?
159
Q

Explosion

A
  •  Combustion with release of gases, which expand with the heat
  •  Very fast
  •  If confined – pipe bomb – shrapnel
  •  Large blast – gases escape - >7000mph
  •  Gale force – knocks over buildings, walls, kills
160
Q

Classifications of explosives

A
  • Based on speed at which the explosive decomposes
    - Low explosives – speed of deflagration (burning) – rapid oxidation, heat, light, subsonic pressure wave.
    - High explosives – speed of detonation – creation of supersonic shock wave, chemical
    bonds break - instantaneous build-up of heat and gases
161
Q

Low explosives

A
  •  Throwing or propelling motion
  •  Normally just burn
  •  Black powder, smokeless powder
  •  e.g. fuse to gunpowder
  •  Lethal when confined - pipe bomb
162
Q

High explosives

A
  • Primary explosives – ultra-sensitive to heat, shock or friction. Detonate violently instead of burn. Primers, blasting caps

- Secondary explosives – insensitive to heat, shock or friction. Burn rather than detonate if
in open air e.g. dynamite, TNT etc.

- Bombs must be detonated by an initiating explosion

163
Q

Explosives

A

- Early days - high explosives – nitroglycerin and pulp – dynamite
- Now ammonium nitrate based e.g.- water gels, emulsions and ANFO (ammonium nitrate
soaked in fuel oil)
- Ammonium nitrate – manure
-> Easily available!
-> Washes away
-> Significance

164
Q

Bombs

A 
- Explosive
- Timers
- Detonators
- Fuses
- Batteries?
- Duct tape?
165
Q

Forensic Toxicology education

A
  •  Require minimum of B.Sc. (Hon) in biochemistry, chemistry or pharmacy
  •  ~16-18 months training period at lab, mentored by a toxicologist
166
Q

What is Forensic Toxicology

A
  • Detection of drugs and poisons
  • Interpretation in terms of physiological and behavioral effects
  • Analytical chemistry & Pharmacology
  • Also some pathology, physiology and biochemistry
167
Q

Goals of the forensic toxicologist

A
  • Assist in establishing the true cause of death
  •  Provide a basis for intoxicated behaviour
  •  Provide a clue to clinical history when the subject is unable or unwilling to do so
  •  Assist in establishing the truth of statements such as “I was high and so I don’t remember”
168
Q

Criminal Cases

A
  •  Murder, attempted murder, manslaughter
  •  Assault, physical, sexual, chemical weapon
  •  Impaired driving
  •  Poisoning, noxious substances
  •  Food and product tampering
  •  Parole and probation violations
  •  What is it?
169
Q

Other types of cases

A
  • Coroner or ME lab – postmortem toxicology – non-criminal
  • Health Canada: Bureau of dangerous drugs
    • > Controlled drugs and substances act violations
  • Private Labs
    • > Employee screening
170
Q

Caveat – “Dose makes the poison”

A
  • ANYTHING can be a poison
  • Depends on DOSE
  • E.g. oxygen, water
  • Raves
171
Q

Toxicological Investigation

A
  • Analytical – what is it?

- Interpretation –what does it mean?

172
Q

Analytical

A 
1. Select specimen
2. Extract compounds
3. Separate compounds
4. Identify drugs/poison
5. Quantitate drugs/poison
173
Q

Interpretation

A
  • When was last dose taken?
  • Was it acute or chronic?
  • How was it taken - i.v., oral etc.?
  • What was the level at an earlier time?
  • What symptoms would be present?
  • Is the level therapeutic, toxic or fatal?
  • How much was taken?
174
Q

Specimen - Blood

A
  • Good for screening, confirmation and quantitation
  • Primary index for drug/poison effects 
  • “Dirty”
  • Invasive, or may not be available
  •  Postmortem redistribution of drugs  - Alcohol production by body after death
  •  Need to collect blood from several sites to compare
175
Q

Specimen - urine

A
  •  Primary fluid for screening and confirmation.
  •  Not so good for quantitation
  •  Excretory products
  •  Indicates prior exposure
  •  Easily available, non-invasive
  •  Useful for postmortem alcohol determinations
  •  Clean specimen
  •  Risk of tampering
176
Q

Specimen - Hair

A
  • Good for screening over many months
  • Controversy over whether IN or ON hair
  • Canada – criminal testing only
  • US criminal and employment testing
177
Q

Other specimens

A 
 Liver
 Kidneys
 Gastric contents
 Bile
 Brain
 Lungs
 Injection site
 CSF
 Bone marrow
 Maggots
 Vitreous humor
 Synovial fluid
 Stains
 Saliva
 Meconium
 POST-MORTEM!!
178
Q

Non-biological Exhibits

A
  • Paraphernalia: syringes, spoons, pipes
  • Residues – powders, stains, food
  • Medicine: prescriptions, pills
  • Seized at scene?
179
Q

Analytical considerations

A
  • No single analytical scheme to detect everything
  • Use a repertoire of standard methods
    - > Modify according to nature of case as well as type and amount of specimen
  • Exclude or indicate the presence of a drug, poison or class of compounds
  • Presumptive then confirmatory tests
180
Q

Presumptive screening

A
  • Rapid
  • Sensitive
  • NOT specific
  • Very useful to exclude a drug or class of drugs and to indicate possible drugs
181
Q

Confirmatory Methods

A
  • Sensitive
  • Specific
  • Combination of chromatography and spectrometry e.g.
    - > Gas chromatography/mass spectrometry
    - > Liquid chromatography/mass spectrometry
    - > Mass spectrometry/mass spectrometry
182
Q

Interpretation

A
  • Drug?
  • Amount?
  • Symptoms?
  • = behaviour
183
Q

Clandestine Labs

A
  • Toxicologist may attend scene
  • Identify dangers
  • Booby traps
  • Identify specimens
184
Q

Franklin Expedition

A
  • Northwest passage
  • Pride of the British Fleet
  • 18 month trip
  • Provisions for 3 years!
  • Library, teachers, musicians, hot and cold running water
  • Canned food!
185
Q

19 May 1045

A
  • West coast of Greenland
  • Baffin Island
  • Never seen again…..
  • Many voyages sent to search
  • 1850, Beechy Island
    - > Cairns of cans 
    - > Old clothing 
    - > Three graves
186
Q

Local Inuit

A
  • Starvation
  • Insanity
  • Violence
  • Cannibalism
  • Autopsies on all three
  • Samples of tissue
  • Very high levels of lead - Old tin cans examined
  • Some burst – meat rotten
  • Some intact
  • Lead solder
187
Q

PrinciplesofDeathInvestigation (5)

A

- To rule out criminal activity
- To establish Cause of Death (Provincial Mandate)
- Information for NOK
 Prevention
- Civil law concerns (life insurance, estate settlement)

188
Q

Coroners…

A
  • Are Sudden Death Investigators
  • Have a medical, investigative or legal background
  • Attend sudden death scenes
  • Do not perform autopsies (but can order them)
189
Q

CoronersAct

A

Section 2‐ Deaths to be reported:

  • By violence (aka homicide), accident, negligence, misconduct,
    malpractice
    ‐ During or following pregnancy;
    ‐ Suddenly or unexpectedly;
    ‐ From disease, sickness or unknown cause that was not treated by a physician;
    ‐ From self‐inflicted illness (all suicide are coroner cases) or injury;
    ‐ In a custodial facility , while detained or as a result of an act of a peace officer in the course of duty
190
Q

Goal of Coroner’s Investigation

A

• To publicly ascertain the facts leading up to and surrounding a
sudden,unnatural or unexpected death
• To make reasonable recommendations to prevent future loss of life
under similar circumstances

191
Q

CORONERS ACT

A

Section 11:INVESTIGATIVE POWERS –
• Take possession and examine the body
• Enter and inspect any place relating to the death
•Inspect information in any records
• Seize anything pertinent to the investigation
•Authorize any person to exercise these powers

192
Q

IMPORTANT

A

• Supreme Court of Canada determined that, if a coroner hands over
blood samples to the police for use in the pursuit of a criminal
prosecution, the subject of that prosecution has had his or her
Charter of Rights and Freedoms violated.

193
Q

Coroners Act

A

Deaths Proceeding to Inquest:
• Deaths that occur while in police custody or lock‐up may proceed to
Inquest
• Deaths that require a public airing of the circumstances or that
involve issues surrounding public safety and confidence, will often
proceed to Inquest

194
Q

Inquests

A
  • quasi‐judicial public proceeding (court)
  • fact‐finding not fault‐finding
  • witnesses give testimony before 5 member jury
  • answers 5 ?’s
  • jury makes recommendationsre: prevention
195
Q

Coroners Act

A

Section 5
A person who has reason to believe that a person died in any of the
circumstances referred to in section 2, must not interfere with or
alter the body or its condition in any way until the coroner so directs (aka no body allowed to touch or move body until coroner says so)

196
Q

POLICEvs.CORONER

A

Police:
• collect of evidence to solve a crime or rule out foul play

Coroner:
• Examines and documents
observationsto establish the
cause and manner of death

197
Q

5Questions?

A
  • Who – Identity of deceased
  • How – Medical Cause of Death (blunt force trauma)
  • Where (they came to their death, not necessarily where they were injured)
  • When (time of death)
  • By What Means – Mechanism of Death (motor vehicle accident)
198
Q

Who?

A

IDENTIFICATION:
visual, BCDL/photos,
fingerprints, tattoos,
personal papers, scars, odontology, height, hair color, previous medical x-rays, DNA

199
Q

How?

A

Medical Cause of Death:
provided by forensic
pathologist if autopsy done or by coroner following examination of history, scene, body
eg GSW to head

200
Q

Where?

A

Where body is found is not necessarily where death occurred
eg. ‘dumps’, OD’s,
homicides

201
Q

When?

A

Time of Death:
cannot be accurately,
scientifically determined due to many factors affecting postmortem changes

202
Q

By What Means?

A

Mechanism of Death:
eg. COD = MBFI
Mechanism of death is
motor vehicle incident

203
Q

By What Means?

A

COD=CO poisoning
Mechanism of death is a
house‐fire

204
Q

SceneExamination

A

Pitfalls!:
Avoid developing tunnel vision….
MAKE OBSERVATIONS INSTEAD OFDRAWING CONCLUSIONS

205
Q

Investigation

A

• History ‐ medical/psychiatric, lifestyle,
alcohol/illicit drug use, known to police
• Scene ‐ gather info for pathologist, info for
family, criminal circumstances, collect
evidence
• Body ‐ a) at the scene
b) at the autopsy (also attend)

206
Q

Postmortem Changes

A

Decomposition: the breakdown of body tissues after death.

Early - blue/green discolouration of skin (but not present in people with obesity)

Moderate - Some swelling, marbling around shoulders, skin slippage

Advanced - Bloating, purging, blistering, veins very visible (marbling), lividity is very dark, eyes swollen

207
Q

Early Decomposition

A
  • Blue‐green discolouration of skin

* First visible overlower quadrant of abdomen over appendix

208
Q

Lividity

A

…is the pooling of blood to the dependant areas of the body after death.

Lividity is usually apparent 2 hours after death and can become fixed with 8 hours.

Blood will not pool into an area where the skin is compressed against a firm surface

209
Q

Rigor Mortis

A

• Enzyme is released into muscle tissue causing
muscle to stiffen
• Apparent within 2 hours after death
• Can take up to 12 hours to progress to full rigor (not an exact science)
• Is accelerated in warm internal and external
temperatures
• Is accelerated with presence of stimulants (i.e. cocaine, amphetamines), physical exertion, fever/sepsis, seizure activity

210
Q

Adipocere

A

• Is the breakdown of the fats in the body.
• Occurs in bodies exposed to water or moist conditions
(ie. bodies in moist soil,
in plastic bags)

211
Q

Degloving

A
  • Body in advanced decomp and skin would fall off with slight pull
212
Q

Overdoses (example of accidental death)

A
  • Central nervous system depressants may cause an individual to become comatose and death may not occur for several hours.
  • ie. Narcotics
  • Incontinence of urine may occur
  • An ingestion of pills may be evidenced by vomitus which may contain undigested pill fragments.
213
Q

Overdoses‐ Foam Cone

A
  • Foam comes out of mouth and develops cone-like appearance
214
Q 
Gastrointestinal Hemorrhage
(GI Bleed)
A
  • Alcoholics with advanced liver disease are at risk for prolonged bleeding
  • Veins in esophagus or rectum can rupture and bleed profusely
  • Ulcers in stomach or bowels can perforate through lining and bleed profusely
  • Blood may be red, brown or black in colour
  • Body may have many visible bruises
215
Q

Classification of Death

A
  • Natural
  • Accidental
  • Suicide
  • Homicide
  • Undetermined
216
Q 
Gastrointestinal Hemorrhage
(GI Bleed) (An example of natural death) (can come out mouth or anus)
A
  • Alcoholics with advanced liver disease are at risk for prolonged bleeding
  • Veins in esophagus or rectum can rupture and bleed profusely
  • Ulcers in stomach or bowels can perforate through lining and bleed profusely
  • Blood may be red, brown or black in colour
  • Body may have many visible bruises
217
Q

Classification of Death (Manner of death) (5)

A
  • Natural
  • Accidental
  • Suicide
  • Homicide
  • Undetermined
218
Q

Natural Deaths

A

• Death primarily resulting from a
disease of the body and not resulting from injuries or abnormal environmental factors
eg. heart attacks, aneurysms

219
Q

Homicide Deaths

A

• Death due to injury intentionally inflicted by the action of another

person. Homicide is a neutral term that does not imply fault or blame.
eg: stellate contact wound

220
Q

Undetermined Deaths

A

• Death which, because of insufficient evidence or inability to otherwise determine, cannot reasonably be classified as natural, accidental, suicide or
homicide.
eg. advanced decomp, suicide vs accident, skeletal
remains, negative findings

221
Q

Undetermined Deaths

A

• Death which, because of insufficient evidence or inability to otherwise determine, cannot reasonably be classified as natural, accidental, suicide or
homicide.
eg. advanced decomp, suicide vs accident, skeletal
remains, negative findings

222
Q

How to determine natural cause of death without autopsy

A
  • Based on whats reasonable. May not be positively known.
223
Q

4 types of search methods (SSZG)

A
  • Spiral
  • Strip or line
  • Zone
  • Grid
224
Q

Different search techniques dependent on situation, what types of situations need to be considered

A
  • Indoor or outdoor
  • Man power
  • Nature of site and scene
  • Approach (path of contamination)
  • Seriousness of Offence
225
Q

What is the spiral technique and when to use?

A
  • Recommended when low in personnel
  • By starting at a focal point and searching in a spiral manner with the aid of a stick and rope, a known distance can be covered.
226
Q

What is the zone technique and when to use?

A

Used to concentrate in specific area

227
Q

What is the grid technique and when to use?

A

Similar to zone, used in smaller areas e.g. searching of small items, ammunition

228
Q

What is the strip/line technique and when to use?

A

Used to search elongated area (roadway)

229
Q

What is the purpose of the identification process?

A

To individualize

230
Q

What is individualization

A

The elimination of all other similar items in the world – leaving only one possible source

231
Q

Why Unknown to known?

A

Perception bias

  • tendency for the human perceptual system to organize sensory data into recognizable forms
  • Seeing something involves knowledge of the object derived from previous experience thus the concept of “expectation” is introduced
  • Extend this phenomena to the comparison of physical evidence, one can readily see that having prior knowledge of the physical characteristics of an object e.g.
  • Studying the known and comparing It to the unknown can result in the same effect
232
Q

What does the ACE-V principle stand for

A
  • Analysis
  • Comparison
  • Evaluation
  • Verification
233
Q

What happens during “A” analysis

A

Unknown item reduced to a matter of its properties, or characteristics, may be directly observable, measurable or otherwise perceptible qualities. This is done before Known item is examined.

234
Q

What happens during “C” comparison

A

Properties and characteristics of the unknown are now compared to the properties of the Known

235
Q

What happens during “E” evaluation

A

Similarities or dissimilarities in properties or characteristics will each have a certain value for identification purposes, determined by its likelihood of occurrence

236
Q

What happens during “V” verification

A
  • Any scientific fact must be able to be duplicated if a scientific process is used.
  • It is standard practice to have all identifications verified
  • This is completed by another FIS technician
237
Q

What are the roles of the forensic toxicologist

A

Detect drugs/poison, interpret in terms of physiological/behavioural effects, assist in establishing the true case of death

Immunology (14 decks)

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