New footprint imaging technique to help solve crimes

Scientists have developed a new technique to create a digital picture of the footprints people leave behind when they stand or walk on a hard surface, which may help forensic experts better track down perpetrator of a crime using footwear imaging.
This new footwear analysis technique developed by researchers at the University of Nottingham in UK could also pave the way for other applications such as clinical studies of gait analysis or measuring how athletes interact with surfaces during high impact activities such as jumping, running or changing direction.
Much like fingerprints we all leave behind our own individual footprint, researchers said. Our gait determines weight distribution as we walk. This, in turn, leads to specific wear and tear on the soles of our shoes.

A conventional technique, known as Frustrated Total Internal Reflection (FTIR) imaging, maps the imprint of bare feet on a hard surface by shedding light through a transparent sheet of material as the foot hits the ground and reflecting it back at an angle.
Using the same technique researchers created more detailed images of the ridges on the sole of a shoe and how these contact a hard surface.
Although specific wear patterns would not necessarily be able to identify a person as the perpetrator of a crime as readily as a fingerprint of DNA it could be used to link them, or at least their shoes, to a particular location-information that could be vital to those involved in law enforcement.

"This technique uses ideas taken from A level physics to form images of regions where shoes contact surfaces. The low cost and ease of implementation of the technique make it particularly appealing for forensic applications," said James Sharp, from University of Nottingham.
The researchers were looking for a device that would allow them to collect images of contact regions of shoes to compare them with footprints at crime scenes - in much the same way as they compare fingerprints.
The study was published in the journal Scientific Reports.