1. BA (Hons 1), Queensland Police Officer, Forensic Services Branch, Brisbane. I acknowledge the assistance of Leo Freney and Peter Clausen of Queensland Health's Forensic Biology Section, of Tim Prenzler and Hennessey Hayes of Griffith University's School of Criminology and Criminal Justice, of the Queensland Police Service, and of two anonymous referees. Opinions herein are not those of the Queensland Police Service. Comments are welcome: .