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Investigative Photography and Crime Scene Sketches. Thanks to Steve Gilbert, MFS Criminal Investigations Program SUNY at Canton. Crime Scene Photography. One of the FIRST investigative tasks!!!. Types of cameras used:. 35mm SLR. Video. Digital. Polaroid. Crime Scene Photography.

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investigative photography and crime scene sketches
Investigative PhotographyandCrime Scene Sketches

Thanks to Steve Gilbert, MFSCriminal Investigations ProgramSUNY at Canton

slide2

Crime Scene Photography

  • One of the FIRST investigative tasks!!!
  • Types of cameras used:

35mm SLR

Video

Digital

Polaroid

slide3

Crime Scene Photography

  • Advantages of photographs

Can be taken immediately

Can accurately depict crime scene

Creates interest

Supports testimony

  • Disadvantages of photographs

Do not show actual distances

Can be distorted

Digital images can be altered

slide4

Advantages of Video Taping

  • Increases Intoxication convictions - DUI
  • Enhances officer integrity
  • Provides officer safety
  • Documents traffic violations
  • Reduces court time for officers
  • Lowers liability for misconduct claims
  • Documents probable cause and evidence
slide5

Disadvantages of Video Taping

  • Records unwanted sound
  • Documents errors made by officers and technicians
  • Officers not always trained
  • Discrepancies with Time/Date stamp
slide6

Types of Photographs

Establishing photographs depict an overall view of the scene, buildings, approach and escape routes, witnesses, etc.

Medium-rangephotographs depict the relationship between objects, concentrates more on the immediate scene.

Close-up photographs depict individual items of evidence.

slide10

Flash photography is often needed during the day. As seen in the photograph, the camera’s eye is fooled by the bright brickwork, while the evidence is in darkness.

slide12

Photographs should contain rulers or objects to help establish the size of the evidence.

In this instance, the known length of the bill can be used as a scale to determine the length of the knife.

slide14

The General Uses of Photography

  • Crime scene documentation
  • Surveillance of people and locations
  • Mug shots
  • Line-ups
  • Laboratory examination of evidence
slide15

Crime Scene Sketches

Sketches are important supplements to photographs and crime scene reports. Sketches….

  • Accurately portray physical facts
  • Relate to the sequence of events
  • Establish locations and relationships
  • Provide an overall picture of the scene
  • Are a permanent record of the scene
slide16

Crime Scene Sketches

The rough sketch is drawn at the crime scene. It is not a finish product, although it does contain measurements and other data.

The finished sketch is often drawn by a draftsman to show proper relationships and scales. The finished sketch is more presentable for court presentations.

slide17

Steps in Sketching the Crime Scene

1. Observe the scene and plan the sketch

2. Measure distances

3. Outline the area (area dimensions)

4. Locate and draw objects and evidence within the sketch

5. Record all details

6. Depict legend, title, scale and direction of North

slide18

Triangulation Method of Locating Evidence

A

8’

10’

Item A is 10’ from the SE corner of the room, and 8’ from the SW corner of the room. These measurements will ALWAYS intersect at item A’s location.

slide19

Triangulation Method of Locating Evidence

A

desk

Evidence must be triangulated to two fixed points. Not using the corners of the room, how would object A be triangulated?

slide20

Triangulation Method of Locating Evidence

A

desk

First, the desk is not fixed, as it is not touching the wall and its location has not been determined. To fix the desk, do this:

slide21

Triangulation Method of Locating Evidence

3’

A

desk

1”

Now that the desk has been fixed, object A can be fixed from two fixed points from the desk, as such:

slide22

Triangulation Method of Locating Evidence

3’

A

5’

desk

6’

1”

Now that the desk has been fixed, object A can be fixed from two fixed points from the desk, as such:

slide23

Triangulation Method of Locating Evidence

A

desk

In this scenario, the desk is flush against the wall. How would object A be triangulated?

slide24

Triangulation Method of Locating Evidence

3’

A

5’

desk

6’

The flush side of the desk is already fixed. One measurement is required to place the desk along the wall. Object A is then triangulated as usual.

slide25

Triangulation Method of Locating Evidence

desk

A

This desk is flush in the corner against both walls. How would object A be triangulated?

slide26

Triangulation Method of Locating Evidence

desk

6’

A

5’

Since two sides of the desk are already fixed, object A is triangulated as usual.

slide27

Triangulation Method of Locating Evidence

desk

6’

A

5’

2’

2’

B

Once evidence is triangulated, it can become a fixed point to triangulate other items of evidence. In this case, object B.

slide28

Rectangular-Coordinate Method

A

15’

B

6’

10’

6’

slide29

Azimuth Method of Triangulation

Tree

340°

160°

40°

Shed

220°

Reverse azimuth:340°-180°=160°

N

Reverse azimuth:40°+180°=220°

W

E

Body

S

Compass

slide30

Administrative Data

LEGENDA. VictimB. RevolverC. Shell CasingD. Blood Stain

TITLECase: 1234-2001Location: Payson Hall, Room 111Victim: State of New YorkOccurred: Oct 31, 2001, 2300Drawn by: Detective GilbertVerified by: Detective Marlowe

Not to Scale

North

Or¼” = 1 foot

slide31

Rules for Drawing Sketches

  • Never measure through space
  • “Rotating” items require measurements at opposite ends
  • Oddly shaped items, such as puddles of liquids, are triangulated from center of mass
  • Do not cross measurement lines
  • Always have the sketch verified
slide32

10”

13”

Since the blood droplets are of no particular defined shape, they are triangulated to the “center of mass”