A retired government forensic analyst on Friday acknowledged that the absence of gunshot residue on the hands of three men killed by police in St Andrew in 2013 did not necessarily mean they had not fired weapons during the fatal confrontation.

The concession came during cross-examination by defence attorney John Jacobs in the trial of six policemen charged with the murders of Matthew Lee, Mark Allen and Ucliffe Dyer along Acadia Drive on January 12, 2013.

Under questioning, the analyst agreed that several factors could affect the presence or preservation of gunshot residue, including movement, handling, wind exposure and delays in securing evidence.