Lack of gunshot residue not proof men didn’t fire on cops, says retired forensic analyst

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.

“Based on the many factors, the absence of gunshot residue does not mean that somebody did not fire a gun,” Jacobs suggested.

“That’s correct,” the witness replied.

The witness had previously testified that no gunshot residue was found on any of the three deceased men. However, she said a small amount of nitrate was found on one of the samples taken from Dyer.

She had also indicated that the presence of nitrate alone, along with the proportion detected, would not be enough to conclude that gunshot residue was present.

Further, she said that all four components — nitrate, barium, lead and antimony — would need to be present, or at a minimum three of them, before a conclusion could be drawn that gunshot residue was present.

Under further cross-examination, the former analyst also accepted that if swabs or clothing were not properly secured, any residue present could diminish or disappear over time.

Jacobs focused heavily on the handling and timing of evidence submitted to the forensic laboratory, particularly T-shirts and gunshot residue swabs labelled NB6 through NB10.

The witness testified that the swabs were received from a sergeant on January 15, 2013, in sealed envelopes, while the T-shirts were separately received on January 23 from another forensic officer.

She agreed that there was a gap of several days between the collection and submission of some items and accepted that improper storage or handling during that period could affect residue findings.

During re-examination, prosecutor Kathy-Ann Pike sought to clarify the distinction between the swabs and the T-shirts after a series of exchanges between defence counsel and the court over dates and labelling discrepancies.

The analyst explained that the swabs arrived sealed and labelled NB6, NB7 and NB8, and included control samples intended to detect contamination during the swabbing process.

She further testified that the laboratory tested for barium, lead, antimony and nitrates — all components associated with gunshot residue — but only nitrates produced positive results in the samples examined.

Asked why additional testing equipment was not used to measure the quantity of the elements detected, the witness said the standard chemical testing protocol employed by the lab at the time did not require it once only nitrates were identified.

She also explained that the composition of gunshot residue could vary depending on the brand of ammunition used.

The analyst said movement of the bodies from the scene to the hospital and later to the morgue could also contribute to the loss of residue, particularly if clothing was handled extensively.

However, she noted that in the absence of significant handling, residue on deceased persons would generally be expected to remain.

Sergeant Simroy Mott, Corporal Donovan Fullerton, and Constables Andrew Smith, Sheldon Richards, Orandy Rose and Richard Lynch are on trial for murder.

The policemen are contending that the three men were killed during a shootout with police.

The trial will continue on Monday.

tanesha.mundle@gleanerjm.com