A novel method for linking reciprocating saw blades, suspected of being used for theft, to a stolen catalytic converter by using toolmarks comparison techniques.

Abstract

In recent years, there has been a significant increase in metal prices, particularly precious metals. Consequently, property crimes involving metal theft, including the theft of auto parts and catalytic converters, have also increased dramatically. The surge in catalytic converter thefts is linked to the use of precious metals, such as palladium, rhodium, and platinum, in their construction and their high price. A skilled thief can easily and quickly steal the catalytic converter by getting underneath the vehicle and, in a few moments, simply cut the exhaust pipes in front of and behind the catalytic converter using a common cutting tool, such as a reciprocating saw. Beyond the high price and the ease of committing the theft, police investigators experience difficulties finding forensic evidence that will incriminate the suspect. Furthermore, linking the cut items, such as the reciprocating saw, is not a simple challenge because of its mode of operation. The cyclic movement of the saw's blade, back and forth, removes a section of material. Therefore, examining a saw mark is mainly based on details relating to class characteristic features rather than individual characteristics. The authors seek to challenge this approach and demonstrate the feasibility of linking, using microscopic toolmarks comparison, cordless reciprocation saw, and the potential individual marks that may have resulted from the tip of its blade on the catalytic converter during the cutting action.