Forensics Final Flashcards
Document
: Is something that contains marks,symbols,or signs that convey a meaning or a message to someone
Ex: Graffiti, Mona Lisa Painting(artwork in general), Classnotes
Questioned document examiners
-identify handwriting, handprinting, signatures, forgeries, identify papers, inks, and writing implements, determined when a document was produced. They identify the individual who prepared the writing or signature on a questioned document
Question Document:
Is a document who authenticity or age, or authorship is called into question
Common and Uncommon Documents
Common type: involve handwriting/white collar crimes)
forgery is the most common (prescription fraud)
Uncommon: Graphology(Twilight zone) determine personality from handwritten; not recognized as science
=
Surfaces and Medium:
Same type of writing surface and medium;(suspect writes sharpie on wall, have them use sharpie to write on a wall)
Uniqueness
- Learned through copybook technique
- 30 handwriting systems taught in the U.S
- Writing Systems: Zaner Bloser or Palmer are most common(copybook system)
- We were not given latitude
Uniqueness of Handwriting: (1) There must be an adequate # of known examples of an individuals writing so that the entire range of variation in the writing is captured. (2) the samples must contain enough individual characteristics to permit identification.
Exmpahsis no longer on letter form but legibility
Evolution Maturity
- 7 year cycle change to writing
- Signature is the most stable item
Factors that Change Handwriiting
- Disease
- Alcohol
- Drugs
- Surface area,medium
- control of pen
Laws of Handwriting ID
Every handwriting is unique(no two signatures are the same
- Variation always exist in an individuals handwriting
Good handwriting
Standard Exemplars:
capture range of variation
- Good,average,and bad writing
- Car notes,class notes,lease,grocery list,passport,checks
Dictated Exemplar:
Told what to write
- To tire you out, tired of faking it; less likely to maintain disguise
Calcification:
teeth developing within gums(reliable determine age)
Eruption:
teeth cut through gums(not reliable)
Probe:
identify where soil been disturbed
Friction ridges:
on fingertips and palms, soles,and toes
- Epidermis
top layer and sheds
Dermis: blood
vessels,sweat glands,nerves,(none of this is in epidermis)(ex paper cut is dermis being penetrated)
Dermal papillae:
undulating surface on top of dermis under epidermis that lock. together; (creating friction ridges on fingers: for grip) unique to everyone Palms and soles of feet
Questioned:
Don’t know whose it is(usally compared to those in a system already
Known fingerprints:
Known fingerprints: recognizable finger prints
Types of Firearms
Handguns
- Pistols (AKA Semi-automatics)
- Revolver
Long Arms
- Rifles
- Shotguns
Gunshot Residue(GSR)
Projectile
Flame
Soot
Burned Gunpowder
Unburned Gunpowder
Gas
Priming compounds
Bullets on Bone
Beveling
*exists are larger than entrances; doe snot have exterior beveling
Distance Determination
Contact
Near Contact
Close
Distance
Contact
- Grease wipe
- Abrasion Collar
- Stellate tear
- Cherry red wound tract
- Gunpowder and soot inside wound
- Muzzle impression
Near contact -
skin to 6 inches away.
-Singing and burning of skin, clothing and hair
-Tattooing/stippling
-Soot in a circumscribed area
- Abrasion collar
-Grease wipe.
Close range
*shots between 6 - 24 inches.
- Stippling/tattooing
- Soot (at closer distances)
Abrasion collar
Grease wipe.
Far Distant
24 inches or more.*
- Abrasion collar
- Grease wipe
- No soot or stippling
- No cherry red wound tract
- No burning or singeing
- No soot or stippling
-grease wipes-
(dirt on projectile)(all 4
n
- cherry red wound :
- Abrasion collar
friction burn around gunshot injuries)(all 4)
Gunpowder and soot:
gets propelled inside wound tract
- Tattooing/stippling:
around gunshot wound tract
Identifying Shotgun injuries
identify area w/ pellet spread
*can’t identify w/ slug
Shotgun injuries
- Pellet injuries
- Shot w/ slug cause major damage(especially self inflictedhead)
- Shotguns are rarely fatal
- Further away less lethal pellets; closer way more damage
- Pellet hole=cookie cutter defect
Gunshot inuries to the bone
- Bone, Glass, Lithics (conchoidal fracture)-
- Radiating fractures:
- Bullet hole and concentric fractures
- Radiation fracture stops at preexisting fractures
- Fractures terminationates at existing fractures
- Can distinguish extrance from exist
- Bullet on bone(Beveling)-exists are larger than entrances; does not have exterior beveling
- Beveling/chattering- removal of bone fragments
(conchoidal fracture)
Bones,glass,lithics
they break in a predictable fashion
Radiating fractures:
start at point of impact and radiate out
-fractures terminate at other fractures
5 R Rule:
Ripples on radial cracks/ R at right angles to the rear
**Easier way: ripples on radial cracks / R at right angles the side opposite impact
- Broken edge: you should see ripples/striations on radio cracks
**Ripples only touch one side of glass, not the other side; at right angles to the rear
- Glass is flexible
Trace Evidence:
anything that’s tiny(paint,dirt and glass)
Pharmacy fold:
contains little pieces of evidence (example eyelash,blood swap,wet condoms(paper will observe fluid
*Majority of glass should be on inside if breaking ito a house(t/f)
True
Glass valuabilty
- Hair
- Fibers
- Fingerprints
- Footwear
- Method of fracture:
- Sequence of events
- Direction of fracture
Method of fracture:
velocity of weapon that hit targer(high velocity=less cracking than low velocity)(ex: less damage caused by gun than baseball bat)
Sequence of events:
radiating fractures terminate other radiating fracture
filaments
wires that determine if headlights were on or off
straight= off/cold
stretched out/wavy= hot and on
silencers(sound suppressor)
- report wave
- shock wave
Report Wave -
Gasses in contact with the atmosphere
Shock Wave
– Projectile travelling faster than the speed of sound
Serial number restoration
Ultrasound
Magnaflux
Electrochemical Etching
Handwriting
surfaces that were writing on, median were writing with are the same; implementing and surface
t/f firing pin impressions are casings
True; cartridges don’t have this
children have more bones than adults
true; (end of epiiphcies are not fused)
Last bone to fuse is called the MEDIAL aspect of the CLAVICAL
Age? At about age 22 or early 20s
Children determine age by generative changes
true
Adults determine age upon degenerative
true
Body wrap in fluid of decomp(blanket/sheet); increase vegational growth(provide nutrients for palnts
true
Body wrap in shower curtain; decrease vegetational growth
true
Yucca
historic African American cemeteries)
Probe:
identify where soil been disturbed and feel for resistance
Auger
produce plugs of soil, evaluate plugs for mottling
Thermography:
method of heat detection
Geochemical study/lipids:
look at soil for fats or proteins if a body had been at location and been move
Night vision:
enhances existing light(night vision requires heat source is false)
Photograph UV:
enhance of injuries/tattoos, causes bones to flourecence
Age of growth:
How long has a body been in an area?
Coffin wood:
will cause degradation to the bone and cause coffin wear
When grave is excavated and backfill, mixing if soils(mottling)
true
(not as compact more air rated)
*Ground Penetrationg radar(GPR):
send and receiving attenae disruption is map shows up as blips
Bone are pourus
true; : can absorb coffin wood
Native American burials are often flex/bundled(fetal position) remains and or covered in occur
Under mounds or rock pile, scaffle burials
true
Can determine age based upon calcification not eruption
true
Excavate a grave:
according to the boundaries that were established by the perpetrator
We can do this bc we know disturbed soil will peel away from undisturbed soil
Tree ring dating
on an archeological site
Branch ring dating
on vegetation that is growing through other types of remains
5 primary layers of soil
: silt (organic material), subsoil,
clay,
gravel,
and bedrock
Scent detectors
develop to produce sensors that will detect methane.
**Used in the Kasey Anthony case
Shrial pin staining:
will cause green staining on the side of the cranium or elbows
Intentional cranial deformation affects cognitive abilities
false
**commonly practice in American southwest by natives
True or false: Cremation will render bones to dust?
False
Cameras and scopes:
can thread into graves or suspicious los to see if there is anything submerged
night vision requires heat source
false
Finger Print pattern
loops(1 core,1 delta) 65%
whirls(1 core 2 delta) 30 %
arches- (0 core,0 delta) 5%
Ridge count:
number of ridges between core and delta is ridge count(ex: 16 ridges count at crime scene eliminates those who don’t have 16 to narrow it down)
Type lines
(the area surrounding the fingerprint pattern)
DO type lines contain individual characteristics
true
Cases will go to court if there are 8 corresponding individual characteristics.
true
Automated Fingerprint Identification System(AFIS) makes fingerprint hit?
False
People make fingerprint hits
Animals: primates, particular chimps, have fingerprints that are indistinguishable from humans.
True
Latent
:Invisible to the naked eye (before the ap of chemicals or powders)
*magnetic powder
Patent:
visible buy use pateterns to make them look better
*8black carbon powder
Plastic:
3-D (fingerprint imprinted in paint, putty, or gum)
toolmarks
take hard substance and press into soft substance(ex: bite mark, hammer in wall,seerial # restoration
Firearm examiners are ballistic
false
Ballistic:
the study of a projectile in flight.
*** Firearm examiners can care less about what it does in the air. They care about what it does to the target (Interaction of the projectile with the target).
Firearm and Toolmark examiners are responsible for the restoration of serial #’s, electronic or engine blocks.
true
muzzles are important in self inflicted gunshot wounds
true
Revolver doesn’t leave evidence behind
true
have to manually dump it
(1) revolvers are less likely to jam than semiauto b/c they contain less moving parts. (
true
(3) it takes slower to reload ammo in a revolver than in an semiauto (unless you use a speed-loader).
true
4) revolvers do not expend firing casings as semiautos, must be done manually
true
. (5) more gsr will be deposited on the shooters hands from revolver
true
Anatomy of revolver:
**Grip, muzzle (becomes important w/contact gunshot wounds like suicides),
Barrel & cylinder (can be rifled, spiral pattern will be cut into it), trigger/hammer is hidden by a slide in the semiauto i.e the firing pin causes primer to ignite
shotgun guns are rifled
false
Pistols:
cases get ejected, load ammo into magazine,
- 13 shots can held by pistol in chamber
**Will leave evidence behind at a crime scene
Because semi autos will automatically expel that cartridge casing
A semiautomatic, automatically discharges or expends cartridges
False, it expends casings
Anatomy of ammo
- Projectile
- Gun powder
- casing
- primer
GSR must be conducted 2 hours after shooting
true; will be inconclusive after 2hr mark(worse evidence)
Primer
3 elements only found in primers(percussion sensitive)
- barium
- antimony
- lead
GSR(Gunshot residue) is only in priming compounds
true
Class characteristics of projectile
- All military ammo must be jacketed
- Type of jacketing
- Caliber
- Shape
- Rifled projectile ten to triangle, handgun projectile dome shape
- Manufacturing
- Location of primer: most ammo has primer in middle, but can be around edges
Inconclusive:
Is indicated when there is “some agreement” of individual characteristics and all discernible class characteristics, but insufficient for an identification.
casing = firing pin impression
true;
- Jacketing:
something put over lead core of projectile
- keeps thee bullet together because lead is soft
**military ammo is jacketed*
individual characteristics of projectile
- Landing grove impressions: scatches sene on jacketing or lead core, scratches come from spiral pattern. (rifling)
- Rifles And handguns are rifled
- Shotguns not rifled
Landing grove impressions:
scatches sene on jacketing or lead core, scratches come from spiral pattern. (rifling)
t/f: shotguns will have landing groove impression
false, landing roove= rifling
Shotguns
- shotguns can shoot slugs and pellets
- shotguns shells have primer
true
class characteristics of casings
- Caliber
- Length
- Manufacturer
- Base stamp info
- Metal
- Shape of nose/neck
Individual characteristics of casing(4)
- Firing pin impression(dimple in primer)(all)
- Breach impression(base striations)(all)
*Two are unique to pistols
- Extractor marks(fingers that grap catridge and move magazine upstairs to firing chamber)
- Injector mark: hooks in base of casing, and comes in firing chamber flips it out
Extractor marks
**pistol
(fingers that grap catridge and move magazine upstairs to firing chamber)
- Injector mark:
hooks in base of casing, and comes in firing chamber flips it out
Breech impression:
is the “dimple” impression, that is right in the middle of the primer. As the firing pin strikes the back of the cartridge, there’s a momentary reverse recoil. Entire base gets marked which are unique to that particular weapon
Projectile
slug or pellet
True or false? Shotgun slugs will have land & groove impressions? The answer is
False because shot guns aren’t rifled and land & groove impressions comes from rifling
True or False? Shotgun shell have a primer?
True
What ammo does shotguns shoot
slugs and pellets
Rifling:
Barrel-has a spiral pattern. To make more accurate in flight. Has absolutely nothing to do w/rifling
Gun Anatomy:
-Barrel (All)
-Trigger (All)
-Grip(All)
-Muzzle(All)
-Sight (All)
- -Hammer(All)
-Firing Pin(All)
Except:
-Magazine and slide(Pistol)
-Revolver(cylinder)
GSR comes from the breaks on the top of the revolver
true
Cartridge anatomy
- Projectile
-Gunpowder - casing
- primer
If you have a cartridge, you hould not have a firing pin impression
true
Things that causes the projectile to be messed up in the weapon?
- Misfire
- ## Reloaded that casing into a new cartridge
cartridges have firing pin impression
false;
- Casing have firing pin impressions
***Cartridges are not fired
Snake shots
-sooto shotgun shell or .22 caliber
Spiral pattern- t
hat cuts through the barrel of the weapon
what comes out muzzle
- Soot-ash
- Flame
- Burn and unburned
- Projectile
- Projectile
- Gases-Co (Primary)
- Barium, Antimony, Lead: used for GSR Testing
- Flakes of gunpowder
Projectile has no Forensic evidence
true
rifling impression
- Spin on projectile, enables you to predict where it will end up on projectile
- As projectile travels down the barrel it creates land and groove impressions
Land- high spots - Groove-low impressions
- Creates an etching and becomes a series of strations
Full metal jacket(FMJ)
preserves landing groove impressions
Holds projectile together
Geneva Convention-In times of war all ammo has to be fully jacketed.
true
Semi-jacket:
lead peaking through
Unjacketed:
coat projectile wears-no jacket
Cop killer” is teflon jacketed will reflect on a bullet proof vest
Fragment might can kill you if it hits you in the right spot
true
In terms of forensic, it be harder to recover unjacketed rounds and will be reduced
true
It will be impossible to trace land & groove off of unjacketed projectile
false(no)
-Abrasion collar:
encircles the bullet hole. Is friction burn caused by the skin being stretched and abraded by the passing projectile
-Stippling of the skin:
may occur from burned or unburned particles of gunpowder being forced into the skin
-Stingeing of the skin or clothes:
this is due to muzzle flash or soot around the entry wound. May be deposited inside (as opposed to around) the wound tract.
Muzzle of the weapon:
may be represented as a contusion around the entry wound
**The wound tract may be cherry red in color due to expulsion of CO
-Stellate tear:
when flames goes inside bullet hole.
**Pressed up against surface (gases has no where to go, there’s bloating of the skin, the skin is stretched to capacity, causes serious of tears)
**msotly sene in heads, not seen in collar bones
Wound Pattern Analysis:
- Slug-major damage
- Self-inflicted- catastrophic damage
- Pellets- rarely lethal
13ft: huge hole (cookie cutter defect)
30ft: pellet spread
10 yards-circle becomes closer
w/distance: they continue to spre
Radiating fractures:
- Terminate at preexisting fractures
- Start at point of impact & radiate out
Concentric fractures:
- Fractures will form a circular marks around the point of impact
- Original fracture that doesn’t radiate
-determine the side that it was hit on
Headshot wounds
- 1st shot will be an entrance wound
- 2nd shot will be an exiting (will have exterior beveling)
- 3rd another entrance wound
- 4th will be an exiting wound (will have exterior beveling and a larger exit wound)
Collection
- Forceps(tweezers
- Vacuums: sometimes may vacuum body
- Tape: tape has stickiness of posted note and stick it and pull it(headrest of vehicle,clothing, skin (like a lint roller)
