Impressions
Tire track
Collection methods
2-D
3-D
Tool mark
Shoe Print
Bite Mark
Objects or materials that have retained the characteristics of other objects through direct contact.
Photography
Fingerprint powder and lifted with tape
Electrostatic dust lifting process
Photography
Casting
Using dental stone or similar substance to preserve the dimensional characteristic of the print.
Typically used in road accidents or escape routes from scene.
Help determine vehicle type.
Ink prints and plaster casts.
Tread pattern, width and depth of pattern, and unique characteristics due to the wearing away are all analyzed features.
Defects or patterns may be left in tools when made or used.
Impressions
Dimensions or impression, ridges or striation patterns, defects, paint chips or metal shards on the tool are all features to analyze.
Scratches
As tools hit a surface the shape of the tool and imperfections in its surface may be left behind as an impression.
As a tool moves across a surface it may leave ridges or striations behind
Determine class or size and brand of shoe.
Depending on the impression an investigator can determine if person was running or walking as well as size based on. the depth of the impression.
Tread patterns, size, and depth. Wear patterns cause by walking form, material defects or damage, and other trace material are all features to analyze.
Bite marks help identify a victim or suspect as well as exclude them from others.
Saliva and/or blood can be left behind and tested for DNA.
Dental x-rays can also be helpful information when identifying suspects.
Maxilla and Mandible
Type of bite mark, characteristic of teeth, color of area estimating time passed by, and swab for body fluids are all features to analyze.