Police Document Everything

• At the scene of an accident, homicide or other crime, police investigators use high-resolution digital cameras to document each and every detail of the incident. Investigators scour crime scenes to identify potentially relevant items, like tire marks, and take pictures using a department-issued digital camera. In many cases, investigators take a series of photographs from a number of different angles; if necessary, these photos can be later used to build a more definitive reconstruction of the scene. If the tire mark is not complete, or it appears to have been degraded, police investigators document the evidence, take pictures, and make notes of any surrounding influences, like wet roads or leaves, that may have affected the transfer of the tire to the road; forensics investigators can later use the responding officer's notes to account for missing portions of the tire tracks.
  
  

Investigators Use Powerful Software

• After responding police officers return their notes and digital photographs to forensic investigators, investigators load the digital photos into a powerful computer that serves a very specific purpose. This machine runs advanced photo editing and analysis software, and allows computer savvy forensics investigators to reconstruct or enhance tire tread using computer aided drafting (CAD) software like Autodesk Revit, AutoCAD or Graphisoft ArchiCAD. According to an article in Forensic Science International, a forensics trade publication, CAD-assisted photo enhancement and reconstruction plays a vital role in matching tire treads, especially when the situation required detailed, three dimensional reconstruction. Interestingly, this process is the same used for other image reconstruction analysis applications like shoe treads, fingerprints and even facial or bodily tissue damage. If the responding officer provided series photographs, multiple photos taken from a number of different angles, forensics investigators can use those photos to create an entire virtual crime scene in three dimensions; using special software, forensics investigators can then virtually explore the crime scene, almost as if they were personally at the scene of the incident, and not subtle intricacies in the tire marks.
  
  

Computers Compare Photos to Databases

• With enough photos and computer aided drafting-enhanced images, cops can perform an automated comparison between the photo and thousands of images contained in a special law enforcement database. According to the United States Department of Justice, forensic investigators use a database known as Treadmate to match crime scene and reconstructed tire images to potential tire models. With more than 5,000 vehicle tire and tread patterns available, the Treadmate database also contains information on typical tire wear and damage in addition to tiny nuances like waves, curves, blocks and zigzags embedded in the tire design. If the automated database comparison locates a match between the crime scene images and the database entries, the Treadmate database can return information including the tire manufacturer, dates when the tire model was available for purchase, and on what vehicles or rims the tire may be mounted. With this information, investigators can make a reliable connection between tire marks at a crime scene and the vehicle type that may have left the marks.