An August memo written to Royal Cayman Islands Police Service senior commanders by a police crime scene technician is raising questions about just how much investigating officers can rely on what’s known as gunshot residue or “GSR” for court evidence.
The 29 August memo was written by former RCIPS Scientific Support Manager Martin Gaule. It was sent to Deputy Police Commissioner Steve Brougham and copied to several other senior officers.
The memo states Mr. Gaule’s “personal view” that GSR evidence should be specifically restricted and that it “cannot safely be used to prove or disprove possession of a firearm where there is no suggestion that the weapon has been recently fired”.
Mr. Gaule writes that the police department, as well as the Crown, might wish to consider the circumstances in which costly GSR analysis is of value to an investigation.
The RCIPS memo was disclosed to local criminal defence attorney Peter Polack by the Crown on 10 October just prior to a court hearing.
“The belated release of a RCIPS forensic report dated 29 August, 2012 on 10 October, 2012 suggests widespread GSR contamination in RCIPS buildings and cars,” Mr. Polack wrote to the Caymanian Compass. “This report will possibly compromise all firearm convictions in which the court relied on GSR evidence in the past several years.”
Contacted about the issue on Friday, RCIPS officials made no response to the issues raised either by Mr. Gaule, Mr. Polack or questions asked by the Compass.
Prior to the memo’s release, personnel responsible for processing evidence at crime scenes did a random sampling for GSR at the George Town Police station. The sample swabs were sent to CARIGEN lab in Jamaica to be analysed.
Mr. Gaule reported that results showed a “high level” of GRS present in one area outside cell No. 6 in the police station and also on the hands of a police officer who is authorised to carry firearms on duty.
“Low levels” of GSR were found in other areas outside cell No. 6 and on the belt of a firearms officer.
Trace amounts of GSR were found on the counter of the police station “custody suite”, on the back seat and glass of a police car, and on the belt pants and weapon of another firearms officer. “While some of these results are not unexpected, the exercise clearly shows that background GSR contamination exists on some police equipment, in police vehicles and in common areas of the police station,” Mr. Gaule’s memo went on. “The presence of such contamination could adversely affect the value of GSR evidence found on a person suspected of firing a weapon who has been in close proximity to such areas or officers.”
Mr. Gaule, who is apparently no longer with the department, recommended a number of corrective actions to prevent any GSR evidence contamination.
He stated that officers in the police USG [armed] unit avoid contact with suspects if at all possible “but only if it is deemed safe to do so”.
He recommended that suspects be transported in vehicles not used by armed officers, specific procedures for swabbing firearms suspects and random swab tests every six months at the police station and of officers to monitor any “background contamination” that may be occurring.
Mr. Polack wrote to Chief Justice Anthony Smellie about the issue on Friday. He did not advise whether any response had been received.