The goal of this research project was to demonstrate the utility of an all-metal detector for locating a buried metallic weapon by detecting and identifying specific types of buried metal targets.
Incorporating geophysical technologies into forensic investigations has become a growing practice. Oftentimes, forensic professionals rely on basic metal detectors to assist their efforts during metallic weapons searches. This has created a need for controlled research in the area of weapons searches, specifically to formulate guidelines for geophysical methods that may be appropriate for locating weapons that have been discarded or buried by criminals attempting to conceal their involvement in a crime. Controlled research enables the testing of geophysical equipment and the updating of search methodologies. The current study conducted controlled testing of 32 buried targets that represented a variety of sizes and metallic compositions. They included 16 decommissioned street-level firearms, 6 pieces of assorted scrap metals, and 10 blunt or bladed weapons. Although all forensic targets included in the project were detected with the basic all-metal detector, the size of the weapon and surface area were the two variables that determined maximum depth of detection, particularly with the firearm sample; for example, when using a high setting, the largest firearms were detected at a maximum depth of 55 cm, but most of the remaining targets were only detected at a maximum depth of 40 cm or less. Overall, the all-metal detector proved to be a good general-purpose metal detector best suited for detecting metallic items at shallow depths. (publisher abstract modified)