Criminalistics: Photography

What are the 6 step methodology?

• Assess

• Observe

• Document  

• Search

• Collect

• Analyze

What do you do in Assess?

gather resources, information gathering.

What do you do in Observe?

Walk through the scene, locate primary focal points, exit/entry points, secondary scene.

What do you do in Document?

Notes, photograph, sketch, measure “fix items” 

What do you do in Search?

look for evidence, in drawers, under carpet, through walls etc.

What do you do in Collect?

using PPE, and clean bags/containers, place items in & seal 

What do you do in Analyze?

use chemicals, powders, road mapping at the scene, analyze at the lab.

What are the 4 types of photos used?

General photographs

Evidence establishing shots (mid-range shots)

Close up shots

Forensic quality photographs

To show the basic layout of the scene, usually from four corners, use undistorted lenses.  Remember you are documenting without visual bias.

General photographs

Shows the item of interest along with a fixed object. Use placards.  Remember isosceles triangle.   

Evidence establishing shots (mid-range shots)

Usually don’t need a scale/ruler, but you want to fill the frame and get as much data on the photo.  ID card, VIN #, License plate etc.

Close up shots

will always be ISO 100, tripod use with trigger release, camera’s digital sensor plane parallel to object and a scale to show precise size.  Fingerprints, footprints, tire tracks, anything that you need precise detail.

Forensic quality photographs

What is part art and part knowledge of what your audience needs

Good Composition

What method should you use when taking photos?

Isosceles Triangle Method (Will help find a true distance of objects)

What are the tools for photgraphy?

Shutter speed

F stop (Aperture Setting) (The depth)

ISO (Light Sensitivity)

Shows a link from the item of interest to a fixed location

With or without placards

Helps avoid orientation problems (Which direction is this?)

Mid-range photographs

Take with and without a placard 

Fill the frame, shoot at 90 degrees, tripod should be used

Use ISO 100

Use a scale for forensic quality 

Forensic quality photographs or close-up

Purposefully under and over expose your phone

Bracket

How much light goes in for a specific amount of time

Shutter speed

What F Stop is a good place to start for most pictures? Which one is used for more depth (Lets in little light)?

F11

F22

Seen as F2-F32

F stop

For every photo opportunity there are multiple exposure combinations to choose from

Law of Reciprocity

What ISO do you use for forensic quality work?

ISO 100

The higher you go on ISO the grainier the photo will be (T/F)

True