Forensic Science - Forensic Photography

What is the primary way of documenting crime scenes?

Photography.

Why is forensic photography important?

• Refreshes memory.

• Corroborates / refutes statements.

• Allows others (jury) to see the scene.

What is the correct order of events at a scene involving photography?

1. Visual examination.

2. Photograph.

3. Notes.

4. Sketches.

5. Recover evidence.

6. Photograph & notes.

7. Package & note.

Why should 2 photographs be taken of an exhibit area?

One before removal and one after removal, to prove recovery and show no other evidence remains.

Name some key items in a forensic photography kit.

• DSLR.

• Zoom lens.

• Macro lens.

• Flash.

• Tripod.

What is focal length?

Distance between lens centre and focus point.

What is ISO?

Sensitivity to light set according to lighting conditions.

What is aperture?

The opening of the lens that controls light.

What is exposure?

The amount of light captured in the image.

What is depth of field?

The range of distances in sharp focus.

What is depth of focus?

How far the lens can move without losing image sharpness.

What does a camera lens do?

Focuses light onto the sensor.

When is a tripod especially needed?

When photographing close objects.

What is a common focal length used in forensic photography?

50mm.

What is wide-angle focal length?

35mm.

What is normal zoom macro focal length?

Around 70mm.

What does ISO control?

Image brightness and sensitivity to light.

What happens when ISO increases?

Sensitivity increases; images become brighter.

What does shutter speed affect?

Exposure and motion blur.

What happens when shutter speed increases?

Images become darker.

What does aperture control?

The amount of lighting entering the lens.

What happens when the f-number increases?

Aperture size decreases.

How does aperture affect depth of field?

Smaller f-number = shallow depth, blur background.

Higher f-number = greater depth.

Why use small apertures at crime scenes?

To keep the whole scene in focus.

What is macro used for?

Close-up detailed images e.g. fingerprints.

Why is having flash important?

The built-in flash on the camera is usually too weak.

What should initial photographs include?

• Exterior building.

• All sides.

• Point of entry.

• Overview of scene.

How should mid-range photographs be taken?

Sequentially, room by room, using a strategy (grid/spiral).

What must mid-range photos show?

Objects in relation to each other.

When should items be photographed?

Before removal.

How should grouped fingerprints be photographed?

1. Whole group.

2. Individual prints.

3. After each is lifted.

What angle should the camera be to the item?

Parallel.

What body photographs are taken at the scene?

• Top view.

• Side.

• Head.

• Wounds.

• Hands.

• Feet.

• After removal.

What must be considered when photographing live victims?

• Permission.

• Privacy.

• Same-sex preference.

What lighting helps capture detail?

Oblique angled light.

What must be used with close-ups?

A scale on the same plane.

When should RTC photographs be taken?

ASAP.

What should be photographed in a RTC?

• Scene overview.

• Vehicle positions.

• Tyre marks.

• Vehicles individually.

• Interior.

• Plates.

• Damage.

• Deceased.

• After material recovery.

What must be recorded with photographs?

• Number.

• File.

• ID.

• Title.

• Settings.

• Enhancements.

What must photographs be to be admissible?

Relevant and properly identified with chain of custody maintained.