Processing
TIRE IMPRESSIONS
Visible impressions: Utilize natural and/or artificial light sources
Less visible and latent impressions: Oblique, coaxial, and polarized light
Photograph tire impressions as part of the overall/mid-range and close-up crime scene photographs. Add photo markers and retake the overall/mid-range/close-up crime scene photographs with the photo markers in place.
Latent dust impressions: Electrostatic Dust Lifter
If impressions are two-dimensional, you can use one of the following techniques to enhance them:
Include a L-shaped scale and a compass in all tire impression photographs. Utilize a tripod with a level to ensure that the camera is at a 90 degree angle in relation to the shoe impression. Fill the photo frame with the tire impression. Use an external flash (or flashlight if you don’t have an external flash available) and take the following series of photos:
Holding the flash at 45 degrees, take the following photographs:
One photograph from each side (north, south, east and west)
One photograph from each corner (northeast, southeast, northwest, southwest)
The adjust the flash to 90 degrees and take the following photographs:
One photograph from each side (north, south, east and west)
One photograph from each corner (northeast, southeast, northwest, southwest)
In total, there will be 8 photographs at 45 degrees and 8 photographs at 90 degrees.
Continue shifting down the entirety of the impression and continuing the documentation for a distance that would be equivalent to one full rotation of the tire.
When possible, collect and provide the original tire for the examiner to use during comparison. The examiner will make the required elimination impressions for their comparison.
If it is not possible to provide the tire, recordings can be made of the tire by inking the tread rolling the tire across paper. Thorough photography of the tire tread with a scale in place and the inked recordings can be submitted as a standard if the tire cannot be submitted.
REFERENCES
Bodziak, William (2008). Tire Tread and Tire Track Evidence: Recovery and Forensic Examination. CRC Press.
Dutelle, Aric (2020). An Introduction to Crime Scene Investigation. Jones & Bartlett Learning.
Fish, Jacqueline et al (2014). Crime Scene Investigation. Routledge.
Fisher, Barry & Fisher, David (2012). Techniques of Crime Scene Investigation. CRC Press.
Gardner, Ross & Krouskup, Donna (2018). Practical Crime Scene Processing and Investigation, Third Edition. CRC Press.
Maloney, Michael & Housman, Donald (2014). Crime Scene Investigation Procedural Guide. CRC Press.
Ramirez, Christine & Parish-Fisher, Casie (2011). Crime Scene Processing and Investigation. CRC Press.