AFTE Store - Toolmarks Which May Lead to False Conclusions

Seven discharged .380 Auto cartridge cases and one bullet recovered at one crime scene were submitted for comparison to a firearm seized at a second crime scene. Of those seven cartridge cases, preliminary examination indicated five were discharged in one firearm while the other two appeared to have been discharged in a second firearm. Test fires of a Davis pistol recovered at the second crime scene were made using laboratory stock. The test fired cartridge cases could only be phased using chamber marks. Six cartridges were submitted with the pistol, one of which bore the AP headstamp. Stereomicroscopic examination of the AP cartridge disclosed markings on the primer surface similar to markings on the AP cartridge cases. It was at that time I realized those markings were manufacturing marks. These marks could easily be mistaken for and identified as breech face markings. The two AP cartridge cases were then microscopically compared to the one AP cartridge submitted with the pistol. Sufficient agreement existed to conclude the primers of all three had been in contact with the same tool, not the firearm.