The tyre track impressions are classified as pattern evidence due to the unique pattern that will leave behind. Just as the shoe polish impressions tin help to track down the brand, style and design similarly the tyre tracks possess the ability to do the same thing. The tyre track impressions can be matched through the searchable databases that are organized by the manufacturer, the FBI or any other agency. Such databases are very helpful for an investigator to determine the type of impression and the brand of the tyre. By this determination, it can be highly helpful to identify the vehicle that the tyres were used for. Similar to most of the evidence, the tyre tracks can aid in the identification of the perpetrator by detecting the suspect at the scene by matching the tyres with that of the suspected vehicle.
Doin’ a number on the marks? Well, it is highly unlikely for two vehicles to leave the same tyre mark because as with the usage and the wear on the tyre changes the impression pattern of the tyre. For instance, a unique wearing of the outer edge of a tyre due to the alignment of the vehicle is off and search unique pattern would be very crucial to the investigation because such impression will only be present in the tyre of the vehicle that was used. Sometimes the identification of a vehicle can be very easy, for example, there can be various tyres used on the same vehicle.
Like fingerprints, the tyre impressions are also classified into the categories of visible, plastic and latent. There are various ways to collect the samples of the impressions. The first type is the visible print; they tin be seen by the naked eye and tin be collected by photography as there is no requirement of the special equipment such as powders. The second type is plastic or three-dimensional print; they tin be collected by creating a cast of the print. A cast of the print is usually created by using a powdered stone material such as general stone and water, as soon as the mixture dries a three-dimensional impression is created. The last type of is the latent print, it is not visible to the naked eye and is usually found on the flat surfaces purchase side walks, roads or sideways. In order to collect search impressions an electrostatic or a gelatin lifter dust printing device would most probably be used. An electrostatic dust print lifting device is a tool that electro statically charges to particles within dust or light soil. The particles are shifted to a lifting film such as the gelatin lifter. This method is the best for the collection of dry or dusty residue impressions from almost any surface. A gelatin lifter is a rubber sheet that tin live impressions off of porous roughly textured and curved surfaces moreover it tin also be used for the collection of prints from the vehicle or the scene. Just like all the other evidence these impressions must also be preserved properly in order to avoid contamination. To compare the prints, it is highly recommended to leave the prints on the vehicle and the samples from the crime scene should be packaged properly.