Science

Purdue Made a Tool to Create 3D Images From Shoe Prints

by Nathaniel Mott
Purdue University Mechanical Engineering

Shoe prints and tire tread marks are found at many crime scenes, and chances are good that any suspect of an investigation wears shoes or drives a vehicle, which makes these tracks an important forensics tool. Now the National Institute of Justice has asked Purdue University to create a device to help police analyze these almost ubiquitous marks, and the result could make it easier than ever to solve many crimes.

A team at Purdue University’s School of Mechanical Engineering said on Monday that they’re working on a portable device that will capture more detailed images from snow and soil. The device will also create 3D models based on the tracks it analyzes, and unlike existing products, it will be able to do so in the field rather than back in the lab. Purdue expects it to cost $5,000; existing products can cost ten times as much.

Purdue’s system works by encoding data in a LED light, having a camera gather that information, and using a laptop to ensure that the entire system is functioning properly. This system has the benefits of requiring just one camera and forgoing lasers that would require investigators to wear protective eyewear. It’s also being designed to ensure that anyone will be able to use it without going through any kind of special training.

This will make the device cheaper, more convenient, and better at analyzing evidence than its predecessors. That’s why the National Institute of Justice will give Purdue University roughly $788,000 over two years for this tech. Shoe print and tire tread analysis are that vital to forensic investigators.

FBI forensic examiner Michael Smith said this analysis “provides an important link between the suspect and the crime scene” but many “impressions are overlooked, improperly collected, or not collected at all” due to police error. Purdue’s tool could change that.

The system follows other efforts to use “death clock” bacteria and improved fingerprinting tech to help law enforcement. It has the benefit of applying to more investigations by virtue of the fact that not all crime scenes involve dead bodies or viable fingerprints.

This diagram explains how Purdue's system works.

Purdue University

It also hasn’t been slammed by the White House, which said in September that bite mark analysis is unscientific. Shoe print and tire tread mark analysis has its drawbacks — sometimes the marks aren’t distinctive enough to match with a single person — but it’s generally accepted as a sound way to link someone to a crime scene.

All of which means that improving this system and using it with other forensics tools could help police find more suspects, lead to stronger evidence, and perform faster investigations because they don’t have to worry about cumbersome systems. The future of forensics technologies is coming. Inverse reached out to the team working on this project to learn more about its plans and will update this post if we hear back.

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