Unit 2

Crime scene processing

barricading of crime scene

1. Integrity

2. Contamination

3. Location indicator

4. Investigation efficiency

5. Legal admissibility

6. To maintain chain of custody

Methods of barricading

1. Physical barriers

   • crime scene tape

   • barricades

   • cones (traffic cones)

   • temporary fencing

   • police vehicles (van)

2. Personal barriers

   • police personnel

   • forensic investigator

3. Natural barriers

   • building, wall

   • large vehicle

   • tree

Perimeters of barricading

1. Inner (hotspot)

   • the actual crime scene where evidence is collected

   • only forensic expert and investigator are permitted

2. Middle

   • staging area for investigator and equipment

   • police and driver are allowed

3. Outer

   • media and public should stay away from the boundary

• best practice for barricading

  • larger area

  • assigned for duty to protect the barricading

• challenges

  • larger area (forest area)

  • media and public interference

  • weather conditions

documenting crime scene

crime scene photography

Photography refers to preserving any object in the form of images.

Forensic photography refers to preserving evidence found at a crime scene in form of an image.

format → .raw, .tiff, .png, .jpeg (best to lowest)

1. Overview

   • Image of each corner to see overall view of crime scene.

   • for an overview of evidences

2. Midrange

   • to show distance between 2 marked evidences

   • photographed at 90° angle.

   • evidences should be visible in the image

   • for location and distancing

     

3. Close-up/short range

   • captured by placing an L-scale near the evidence and the camera at a 90° above evidence.

   • for length, breadth and detailing

   • 
     

Photogrammetry → 3 dimensional rendering of images captured at the crime scene.

→ distancing and location

• Challenges

  1. light conditions

  2. Surface of evidence

  3. weather conditions

  4. underwater photography

  5. arial photography

videography

video refers to a collection of numerous photos in a sequence.

videography → preservation of video

• overview

• mid range

• short range/ close up

crime scene notes

Journal observation →

1. Case number

2. Date and time of arrival

3. Location

4. Weather condition

5. Lighting condition

6. Crime scene type

   • Indoor, outdoor or vehicular

7. Reporting officer or investigator name

8. Other officer

Initial observation →

1. Entry and exit point

2. Position and condition of body (if available)

3. Presence of odour

4. Environmental conditions

   • temperature and humidity

5. Visible evidence

Documentation and scene processing →

1. Sketching, Photography, Videography

2. Witness statement collection

3. Evidence collection

   • 
     

     

Action taken →

1. Search method used

2. Processing techniques

   • lifting of fingerprints

   • swapping of blood

3. Safety precautions

   • gloves

   • ppt, etc

4. Specialist involvement

5. Final notes and scene release

6. Crime tapes removal

crime scene sketching

1. Triangulation method

   • measure the evidence distance from a fixed object or an object that cannot be moved.

   • must form a triangle

2. Baseline method

   • draw an imaginary line across the room, ideally near the most amount of evidences.

   • then take the perpendicular distance from the evidence to the baseline.

   • also measure the distance between all evidences on the baseline.

3. Polar method

   • In cases where only one reference point or fixed point is present.

   • using distance from fixed point and then measuring the direcction using a compass.

search patterns

strip method

grid method

zonal method

• time consuming

• crime scene is thoroughly searched

spiral method

spiral inward

• out to centre

• 
  

spiral outward

• centre to out

• 
  

wheel method

• For outdoor crime scenes

• it is time consuming, so it is not used generally.