Footwear Evidence. Objectives: What is footwear evidence? How is it involved in crime scenes? How...

Footwear Evidence

Objectives:

What is footwear evidence? How is it involved in crime scenes? How is it collected? How is it analyzed?

What is footwear evidence?

Different shoes will leave behind prints of different sizes and patterns.

Footwear Evidence

Three different types of shoe prints:

1. Three dimensional impression Shoeprint made in soft material (dirt, snow) Requires making a cast of the print Composition of dirt

or snow will determine the detail of the impression.

Footwear Evidence

2. Two dimensional print (visible) Dirt or other material picked up by shoe and

deposited onto flat, hard surface. Variety of surfaces

and materials deposited makes recovery of these prints complex.

Three different types of shoe prints:

Footwear Evidence

3. Two dimensional print (latent) Can leave behind barely visible dust Can leave impression in polish/wax/dust

Three different types of shoe prints:

Footwear Evidence

3. Two dimensional print (latent) Can leave behind barely visible dust Can leave impression in polish/wax/dust

Three different types of shoe prints:

Footwear Evidence

How are shoe prints evidence?

Most suspects wear shoes. Footprints are always left, it is whether

they can be located and differentiated from other prints.

Burglar

Shoes

Footwear Evidence

What information can shoe prints provide?

Link suspect or victim to scenes Link two crime scenes

Gait or Tracking information?

Footwear Evidence

Location of prints can: Lead to more evidence Refute alibis

Recovery of Footwear evidence

All shoeprints should be recovered from the scene as soon as possible (Transient evidence).

Scene should be controlled to prevent destruction of evidence.

Footwear Evidence > Collection

Recovery of Footwear evidence

Some prints can be visualized by darkening a room and using a bright light at a low angle.

Footprints should be documented: Location recorded and photographed

Footwear Evidence > Collection

Recovery of Footwear evidence

Objects with footprints should be removed if possible (paper, glass)

If can’t be removed, an examination quality photo should be taken.

Ruler: allows for enlargement to real size

Footwear Evidence > Collection

After photo, 2-D print can be lifted:

Electrostatic Lifting: A charge is used to lift dry

materials from surface to black film.

Lift provides more contrast Non-destructive Photographed for evidence

Footwear Evidence > Collection

After photo, 2-D print can be lifted:

Dusting: Fingerprint powder can visualize print Lifted with adhesive or gelatin Photographed for evidence

Footwear Evidence > Collection

3-D impression can be highlighted

Spraying with colored wax spray

Footwear Evidence > Collection

3-D impression should be cast

Cast picks up detail; is durable

Cast after photo Use dental stone

Footwear Evidence > Collection

Enhancement Methods

If footprint is made of blood, TMB or other color changing reagents can help visualize.

Footwear Evidence > Collection

Analysis of Footwear Evidence:

Class Characteristics can be used to eliminate a suspected shoe or suggest a shoe could have made the impression.

Size Pattern

Suspect shoe or test impressions compared.

Footwear Evidence > Analysis

Analysis of Footwear Evidence: Individual Characteristics can be used to

identify an exact shoe. However, these can change over time.

Footwear Evidence > Analysis