FKA 1 Flashcards

1
Q

According to RCMP FIS policy, is ‘probability of Identification’ is permitted on comparisons (excluding fingerprint).

A

We are not allowed to provide probability. We have determined opinions we can provide for physical match and impressions.

5 for footwear impressions and 4 for physical match.

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2
Q

Precautions for mixing Potassium Thiocyanate for scene exhibits.

A
  • Rubber gloves
  • Safety glasses
  • Lab coat
  • Fume hood
  • Eye/skin irritatant
  • Wash with mild soap/water 15min
  • Maintain personal hygiene after exam/before meals
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3
Q

First aid measures Diazafluoren-9-one

A
  • Inhalation: Fresh air
  • Swallowed: Rinse mouth water, drink lots of water
  • Skin contact: Wash area with soap/mild detergent for ~15min
  • Eye contact: Remove contact lenses, flush water until contamination ceases
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4
Q

How does digital camera capture an image

A
  • Aperature opens front of camera
  • Light enters through lens
  • Brought into sharp focus on an image sensor (CCD or CMOS)
  • Light converted into electrical signals called pixels
  • Pixels are digital squares composed of a number based on the intensity of light rec from sensor
  • Electronic image stored in electronic format such as RAW, TIFF, or JPEG
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5
Q

What is PPI

A

Pixels Per Inch
Measurement of pixel density (resolution) of an electronic image, contains a series of #’s which describes its colour or density

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6
Q

What is DPI

A

Dots Per Inch

Unit of measure in which the # of dots can be placed in a line in a space of 1 inch

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7
Q

Difference between PPI & DPI

A
DPI = Dots per inch
PPI = Dots per inch

A given DPI does not always have the same resolution as often move dots are required to create a single pixel, which varies from device to device.

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8
Q

What is CMOS

A

Complimentary Metal-Oxide Semicinductor

-Type of sensor used in digital photography

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9
Q

Describe contrast of an image in regards to digital photography

A

Difference between the darkest and lightest areas of an image

Greater the difference, the higher the contrast

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10
Q

What is digital noise and the effect on an image

A

The degradation of a digital image which can appear as ‘speckles’ on a photo.

Caused by long exposure times, high ISO setting or other factors such as temperature

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11
Q

What is red eye in photography

A

Caused by flash which glares back from the subjects pupils.

Caused as a result of high density of blood vessels directly behind the pupils at the back of the eye

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12
Q

What are artifacts in digital photography

A

Caused by the sensor, undesirable changes to a digital image

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13
Q

What are the tonal ranges of a digital photograph

A

1) Highlight
- Bright areas within a photo that still maintain detail
2) Shadow
- Darker areas of the image that still maintain detail
3) Mid-tones
- Neither shadows or highlights; middle value of luminance

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14
Q

Why is the use of a flash useful in daylight

A

Reduce harsh shadows from strong sunlight

Fill flash can be used to illuminate dark or shadowed areas of interest

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15
Q

Using a digital camera, name 2 ways of correcting the white balance when the auto setting doesnt accurately record the colours of items

A

1) Grey card reading

2) Adjust the white balance setting to the appropriate light setting
- Incandescent, fluorescent, daylight

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16
Q

Formula to determine the maximum printed size to create a ‘good’ quality print of digital image

A

Divide the image size in pixels by 300

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17
Q

How do you ensure the retention of the integrity of digital photographs obtained at a crime scene

A
  • All images recorded consecutively & continuously
  • no images are ever deleted
  • All images are downloaded to folder ‘originals’
  • All images stored on archival quality write-once CD-R or DVD-R
  • Stored in KME
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18
Q

To photographically record a crime scene, what minimum two standards must your digital camera be able to provide?

A

1) Minimum resolution of six mega pixels

2) Ability to capture RAW images

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19
Q

What are the standard items of PPE for safe guard at many crimes scenes

A

Gloves, mask, glasses, Mylar suit, booties, issued pants, long sleeves (when applicable)

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20
Q

List four problems that may occur if the crime scene is not properly secured or protected

A

1) Unknown persons may destroy evidence
2) loss of continuity of evidence
3) evidence could be hidden or removed
4) evidence may be deemed in admissible in court

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21
Q

Five basic patterns used to search a crime scene

A

1) Circle or spiral method
- beginning at a point on the perimeter, moving through the scene using a spiral pattern. Can utilize 1 to 2 persons

2) Strip/line method
- Area is divided into functional strips/lanes
- Strip: beginning at either end, searcher moves down the strip and reverses direction at the end of each strip (1-2 persons)
- Line: beginning at either end, a line of searchers moves down the line in a continuous single direction (larger group)

3) Grid method
- Similar to strip and search, area is divided into functional strips, then subdivided at 90° angles to each other. The surgery starts at the outer most strip and move up and down similar to strip method

4) Quadrant/ zone method
- variant 1: Confined spaces, areas not easily search by patterned movement. Good for vehicles, breaking down each area into a zone and label
- variant 2: Larger seen. Area is divided into quadrants/zones which can then be searched using another search method. Can assist in triangulation method of measuring locations of exhibits or items of interest by first properly staking and measuring the quadrants/zones

5) point to point
- Searcher determines what order they choose to deal with primary focal points and evidence. The path is clear to the first focal point, then immediately around it. Path is then cleared to the next focal point, so on and so forth until scene is complete

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22
Q

Upon arrival to a crime scene what order would you conduct the investigation

A

1) Take notes of location, persons present date/time
2) obtain information from investigator and conducted a survey of scene
3) photograph crime scene
4) Examine the exterior for evidence
5) Examine interior for evidence
6) Photograph the individual pieces of evidence seized
7) Prepare a report and advise investigator

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23
Q

What potential evidence could be obtained from the comparison of glass fragments seized from the scene and from the suspect

A

Can’t determine if the fragment is in the glass. It is glass, the type of glass can be determined and finally a physical match may be able to be completed

24
Q

Where are glass Fragments to be sent for analysis and what main factors need to be taken into consideration

A

The RCMP does not except glass fragments for analysis. If a unit requires glass fragment analysis, depending on the seriousness of the offense, they would have to locate a private lab

25
Q

When the point of entry is a broken window is it important to make note of how much glass is located on either side? Why?

A

Yes. As a pane of glass breaks, most pieces will move away from the source of impact. However, the pane will reach a point of stress where the glass failed and as a result, the pane will rebound, causing some glass particles to move towards the source of impact. These particles may end up on the suspect.

26
Q

If a suspect is arrested shortly after an offence involving broken glass, what procedure would you use to collect fragments from that individual

A

If the suspect has hair, facial and/or arm hair, it should be combed with a clean sterile comb seated with cotton. The suspect should be standing on clean examination paper

The suspect should remove clothing over clean examination paper and once completed the paper should be secured along with cotton using a pharmacist fold

27
Q

Why should the point of entry be examined first at the scene of a break and enter?

A

Potential for fingerprints and or DNA evidence, footwear impressions, tool marks from objects/tools used to assist in gaining entry. It is likely the suspect spent some time in this area and the most likely location where evidence

28
Q

What common methods will you use regularly to document a crime scene

A

1) photography
- overall, mid range and close up
- With/without scales/markers

2) video
3) Sketching/measurements
4) Notes
- arrival/departure
- transient evidence (weather, sounds, smells)
- of evidence (FP, Footwear, etc)
5) Reports

29
Q

What details should investigative notes contain with respect to your scene

A

Time, date, location, persons/officers present, witnesses, objects and areas of interest, sketch and document thoroughly all actions and observations made

30
Q

What are three basic photographs associated with crime scene photography

A

Overall, mid range, close up

31
Q

What is the purpose of mid range, evidence establishing, photography

A

To show items of evidence in relation to other fixed features within the immediate area of the item; they are more specific and more visible. These photos can be linked back to the overall shot to show its location within the scene

32
Q

Why is it necessary for you FIS to speak with witnesses and or victims of a crime

A

To be able to clarify what items/injuries are present or not present to benefit the overall investigation into remain objective and unbiassed

33
Q

Describe the reason it is necessary to record the environmental conditions when at the scene

A

Environmental conditions can cause changes to the scene, preserve or accelerate decomposition of evidence. Documenting the overall conditions upon arrival provides a record of these as ‘when found’ by the Officer

34
Q

What should be marked on an exhibit when it is recovered

A

1) Time and date it is recovered
2) what it is
3) where it was located
4) file number
5) exhibit number
6) name and initials of recovering person

35
Q

What is the benefit of using a rubber casting compound to record Tool marks

A

It allows a three dimensional scratch, gouge, cut or abrasion to be casted three dimensionally which can then be sent for tool Mark identification. This process can assist in identifying what type of tool may have caused the marks, complete comparison of a tool that was located to potentially identify or screw the tool in the investigation is causing the marks

36
Q

What is the most effective way to visualize possible dust prints/impressions?

A

Oblique lighting

37
Q

What is the method for collecting impression evidence located within standing water

A

Dental stone. As the forensic officer will not be able to properly calculate the amount needed, they will continually add dental stone to the area of standing water until it is like a thick milkshake texture and allow to dry as normal, making the applicable marking as you would for footwear impressions

38
Q

What is the purpose of a scene sketch

A

To provide a rough reproduction of the scene as found; provide a bird iview showing the relative position of objects and evidence at 18; says the courts and explaining more complex examinations Via visual aid

39
Q

What should you record with respect to livor Mortis? Why is it necessary to record the presence or lack of these conditions?

A

Lividity is the discoloration of the skin caused by pulling a blood due to gravity after death. Generally in the lower portion of the body. This causes a purpleish – red discoloration of the skin, dependent upon how soon the body is discovered after that. It is a gradual onset, but not less than 30 minutes; very noticeable after four hours and becomes prominent after 8 to 12 hours. Recording the presence or lack there of can assist the investigator in determining the approximate time of death and whether or not the body was moves

40
Q

Describe the term stippling and its potential significance to a death investigation

A

A condition in which partially burned or unburned gun powder is driven into the skin. Stippling patterns are helpful to the medical examiner in determining the approximate distance between the muzzle and target

41
Q

What is the typical appearance indicated by an exit wound

A

Exit wounds are generally larger and asymmetrical than that of the entrance wound. The projectile once it enters a subject slows down as it proceeds through, breaking apart or changing appearance as it ricochets off different services. As it reaches the end of its trajectory, the force necessary to exit is higher than the entry, that the exit wound is larger and considerably more destructive. There is usually no soot or stippling with an exit wound

42
Q

What is meant by pugilistic attitude/stance

A

It is a position generally found in burned bodies which has the appearance of a boxers stance in that flexion of elbows, knees, hip, neck and clenching of hands into fists is caused by the high temperatures of a fire which causes the muscles to stiffen/shorten

43
Q

In a criminal investigation, why is it important to photograph the whole body of a deceased person

A

Accurately records the body as it was found and provides the ability to refute any claims of additional changes/injuries made later

44
Q

Describe in detail what steps you will take to examine a body and prepare for removal from the scene

A

1) Photograph extensively the body in situ
2) document:
- position of body
- clothing
- visible/apparent injuries
- Document whether rigor mortis has set in
- Document stage of post Mortem lividity
3) recover physical evidence
- forensic light source used on body
- swabbing any bloodstains inconsistent with scene
4) bag hands and feet, head if applicable
5) corner/medical examiner on scene
6) body removal
- treat as an exhibit
- secure body bag with seals
- lock casket/crypt
- maintain continuity

45
Q

What methods would you Use to record a faded, suspected bite mark on the victims shoulder at the morgue

A

Forensic light source and adjust the white balance on the camera to properly capture the image

46
Q

At the scene of an underwater search where a firearm Has been recovered by the dive team. To prevent/corrosion how should the exhibit be package for submission to the firearms unit

A

1) Never disassemble, reassemble or alter the firearm in anyway before submitting it to the lab
2) dry wet ammunition and components before packaging
3) Clean seized firearms contaminated with ice and snow and mud water or wet foreign material in a manner that does not alter metallic surfaces
4) rents firearms in hot water to flush off for material and then air dry
5) do not use pull Throughs, brushes or other cleaning devices to clean the barrel or other metallic parts of the firearm
6) Apply oil to all metallic surfaces to protect against corrosion

47
Q

What section of the laboratory will conduct tool mark comparisons

A

Fire arms and tool mark identification section

48
Q

Why is it necessary to photograph fingerprints before lifting

A

When lifting fingerprints, there is always a possibility of damaging the impression while completing the lifting process. Detail may also be lost when the impression is lifted, or the quality of the impression on the left may not be as clear as the impression left on the surface

49
Q

What was Alphonse Bertillon’s contribution to the identification of criminals

A

He was a French police officer, who applied the anthropological technique of anthropometry to law enforcement.

Subsequently created the anthropometry classification system in 1882

50
Q

During the course of Hales research on growth of friction skin he Repeatedly refers to the CR length; what is he referring to when referencing CR?

A

CR equals Crown to rump length. A measurement of human embryos and fetuses from the top of the head (crown) to the bottom of the buttocks (rump)

51
Q

Herald Cummins’ suggest in his paper that a certain anatomical structure of the hand influences the topography of friction ridge patterns; which structure is he referring to?

A

Volar pads. The pads may be regarded as a feature more primitive than the dermatoglyphics. They determine the topography of patterns in the forms which possesses Ridged skin

52
Q

Harris Hawthorne Wilder

A

1864-1928

  • 1896; researched monkeys, noticed resemblance of friction ridges to humans
  • First to suggest that the centres of disturbances of primate friction ridge formations, patterns, represents the locations of volar pads
  • 1918; co-authored personal identification with the Bert Wentworth; stated patterns of friction skin or individual and taken together, impossible to duplicate in another individual. The separate ridges, too, show numerous details with her also so individual that a small area friction skin, taking even in the most featureless portion, cannot be matched by another piece.
  • Basis of qualitative and quantitative analysis of friction ridges found in this book as well
53
Q

Inez Whipple

A

1871 - 1929

  • 1904; published article, the ventral surface by Mammalian Chiridum. Article was the landmark Inn field of genetics/ridgeology
  • described the evolution of friction skin and its development as mankind evolved
  • All mammals have same arrangement of boulder pads on hands and feet; one on each finger, for inter-digital areas, one on each side of palm
  • mammals first lost hair from scales on volar surfaces, volar surfaces fused into rows; ridges evolved according to need of friction scan for Locomotion/grasping
  • ridge patterns are affected by external forces and pressure from neighbouring developing ridges. Friction ridges develop at right angles or possible direction of Locomotion; slippage was the single factor of evolution
54
Q

Harold Cummins

A

1893 - 1976

  • conducted extensive research of friction ridge skin
  • examined fetuses in various stages of growth/health
  • contributions to modern understanding of formation/development of volar pads
  • Volar pad regression occurs concurrently With beginning of friction Ridge development
  • Size/location/growth/configuration of volar pad affects friction Ridge development and overall pattern configuration
  • disease/birth defects have affect on volar pad growth
55
Q

Alfred Hale

A

1952

  • Published thesis: Morphogenesis of the Volar Skin in the Human Fetus
  • examined cross sections of fetal skin; described formation of friction ridge during fetal development and differential growth friction ridge which forms major premise of friction ridge identification
  • Explain the formation of primary and secondary ridges; determine the timing parents is a primary and secondary ridges
  • Demonstrated differential growth plays major role in establishment of morphology of volar skin
56
Q

Michio Okajima

A

1976

  • paper; dermal and epidermal structures of the volar skin
  • established presence of dermal papillae in double rows under the epidermal friction ridges
  • as persons age, structures become more complex and double rows no longer discernable
  • Studied incipient ridges and determined they were primary ridges that had not fully developed