September 1998 Volume 31 Number 3

GUNSHOT RESIDUE-SIMILAR PARTICLES PRODUCED BY FIREWORKS

The fireworks industry uses compounds of lead, barium and antimony in the manufacture of a variety of pyrotechnic devices, with all three elements sometimes being present in the same device. As these elements are used to identify gunshot residue (GSR) particles, the possibility exists of some of these devices producing particles which could bear some resemblance to GSR. During the course of this preliminary study, fireworks were found that generate such GSR-similar particles, those particles being found both on the hands of professional fireworks technicians, and in the combustion plume of consumer-grade devices. Further work will be required to determine any impact such fireworks might have on GSR analysis and interpretation.

DNA PATERNITY TESTING IN CANADA LABORATORY ERRORS AND THE NEED FOR MINIMUM STANDARDS

This paper describes an independent review of three DNA paternity cases originally investigated by a private paternity testing laboratory in Ontario. Discrepancies were noted in all three cases, two of which were shown to be false exclusions of paternity. These cases signal the need for minimum standards of practice for parentage testing laboratories in Canada.

IDENTIFYING BIRD SCAVENGING IN FLESHED AND DRY REMAINS

Differentiating postmortem artifacts produced by natural taphonomic processes from perimortem trauma is crucial in accurate crime scene interpretation, particularly in cases involving the advanced decomposition of remains. Carrion experiments reveal that repeated, extensive scavenging by common birds such as magpies and crows can alter or obliterate evidence of perimortem trauma as well as create postmortem artifacts similar in appearance to penetrating trauma. The location, extent and pattern of damage, as well as characteristic wound morphology in soft tissue and bone, aid in the accurate identification of bird scavenging. Differentiating bird modification to bone from that of rodent and carnivore is illustrated, and the role of birds as agents of transport is compared with that of other scavengers. A case study is presented in which bird, canid and rodent created artifacts on bone are evident.