What is Swgtread?

The documents below are the standards and best practices published by the Scientific Working Group for Shoeprint and Tire Tread Evidence (SWGTREAD) for the collection, preservation and examination of footwear and tire impression evidence.

What is the history of footwear impression comparison?

According to literature, footwear identification dates back to 1786 in Scotland. The first case was worked by a local police constable and according to the circumstances, it could be argued that anyone can observe footwear impression evidence, compare features, and make positive identifications.

What is low cards exchange principle?

From Wikipedia, the free encyclopedia. In forensic science, Locard’s principle holds that the perpetrator of a crime will bring something into the crime scene and leave with something from it, and that both can be used as forensic evidence.

What are footwear impressions?

Footwear impression marks – the mark made by the outside surface of the sole of a shoe (the outsole) – are distinctive patterns often found at crime scenes. They are among the most commonly found evidence at crime scenes and present more frequently than fingerprints.

What are the 2 types of impressions?

The next step is photographing the general area in detail as well as any specific evidence that is found, such as a footprint or fingerprint, before it is altered or collected. There are two main types of impression evidence you’re likely to find at a crime scene: two-dimensional and three-dimensional.

What are Toolmarks?

A toolmark is any impression, scratch, gouge, cut, or abrasion made when a tool is brought into contact with another object. Toolmarks can take the form of a negative impression (stamping type) or abrasion (friction type) mark. Some marks are combination of both features.

What are forensic footprints?

For years, criminal investigators and forensic scientists have used fingerprints to determine identity. More recently, footprints have been discovered to be an equally reliable identifier. Every person’s foot has a unique set of ridges that make up a print unmatched by any other human being.

How are shoeprints Analysed?

Examiners or investigators use powders, chemicals or alternate light sources to find these prints. Examples include shoeprints detected on a tile or hardwood floor, window sill, or metal counter, or tire tracks detected on road surfaces, driveways or sidewalks.

What can Footwear evidence tell us?

Manufacture, model and approximate size of footwear: Footwear impression can show the design elements (shapes, patterns, arrangement) that form the outsole design. These can be compared with a footwear outsole database to identify the model of footwear that made the impression.

What did Locard establish 1910?

In 1910, Locard succeeded in persuading the Police Department of Lyon to give him two attic rooms and two assistants, to start what became the first police forensic laboratory.