Tire tracks are often overlooked at crime scenes or thought of as an after thought. However, these can be extremely telling and helpful for a case. There are numerous elements you can look at and review in order to determine if a tire tread matches tracks or if they belong to a particular vehicle.
Documentation
Documenting tire tracks is relatively easy. Ensure that you photograph with a view of the scene and the tracks in relation to the scene as well as many closeups. When you photograph the closeups always put a scale down, parallel to the track for comparison. If you don’t have a scale use a pen; as long as there is an item that may be compared to the track that is all that matters. (and always take photos from a 90 degree angle)
Tire tracks and tread may be compared to photographs but in some cases you will want to cast them for better detail. This is particularly important when not only the tread of the tire is key but also the type of wear on the tire. When you cast a tire track the casting stone or dental stone will bring out those areas of wear.
Evidence
Using tire tracks as evidence means you will have to have a comparison vehicle tire. There are databases for this type of information and of course if you have a suspect vehicle than you may go through the proper channels in order to compare that. Ensure that when you compare tread with tracks you include measurements of the gaps or creases in the tire. (this is why good, quality photographs are so important) Mention every little detail of the print or pattern of the tread and document each observation. This way if it the evidence ever goes to court you will have all of the information possible from your observations.
Case Evidence
At the very least, evidence of tire tracks can prove a suspect was at the scene at some point. The ability to place your suspect at a the scene of the crime is a huge break in a case and sometimes all it takes is a little attention to detail.