Crime Scene Investigation

Condemnation before investigation if the highest form of ignorance

Albert Einstein

CSI

Process of collecting evidence from expected scene of crime.

Can take place at primary, secondary, or tertiary locations.

Process of CSI

1. Photography and Sketching

2. Evidence Collection

3. Evidence Processing

It is their job to tell the story of what happened at the crime scene.

Crime Scene Investigators

Initial steps of CSI

1. Walk through the entire site

2. Keep hands in pocket or behind back, do not touch evidence

3. Note and observe your surroundings

Crime Scene Photography

Images must be accurate and unbiased.

Photography may help the jury see what the investigator saw.

• photograph fragile areas first

• photograph at a 90 degree angle

• use a scale for up close images

Important evidence should be photographed at least 3 times:

1. where it is

2. 90 degrees without scale

3. 90 degrees with scale

F-stop

Also called Aperture.

Changes how big the lens opening is, influencing how much of the picture is clear and in focus.

Shutter Speed

Determines how long the shutter remains open.

Impacts how blurry or clear moving objects appear.

A shutter speed of 60 allows light in for 1/60 of a second.

Depth of Field

Controls how things in the photo are focused.

The smaller the lens opening the greater the depth of field. (f/22)

The larger the opening the smaller the depth of field. (f/1.8)

Detailed Search

Use a search pattern (grid, spiral, strip)

Search for evidence from general to specific

Several methods for searches:

• zone

• grid

• strip

• contracting and expanding spiral