An expert on gunshot residue told the Supreme Court that particles found on the hands of a defendant did not necessarily mean he had fired a gun.

Tarah Helsel, a gunshot residue expert with the US-based RJ Lee Group, said tiny fragments found on Kiari Tucker could be the result of the defendant being near a firearm being shot, or could have been transferred from another source.

While Charles Richardson, for Mr Tucker, suggested that the number of particles found were more consistent with cases of transfer, the witness denied that was the case.

“It’s not any more consistent with transfer then it is the other two scenarios, the discharge of a firearm or being close to a firearm when discharged,” she said.

Mr Tucker, 27, has denied the November 3, 2017, murder of Morlan Steede, 35, who was fatally shot in the Deepdale area of Pembroke.

He also denied the use of a firearm to commit an indictable offence.

Earlier in the trial, the jury were shown CCTV footage from about 9.40pm that day which showed a man in black clothing and a motorcycle helmet chase a man in a white shirt down One Way Deepdale and on to Parsons Road.

As the figures ran, flashes of light could be seen coming from the end of the man in black’s outstretched hand.

Mr Tucker was arrested by armed officers the following day after police found him under a pile of clothing in a bedroom closet.

On Tuesday, Ms Helsel told the court that she tested a number of swabs collected by police as part of the investigation.

She said that several particles characteristic of gunshot residue were discovered on swabs from Mr Tucker’s hands, along with a pair of jeans, a red and black handkerchief and a black shoe.

Tests also revealed even more particles that were “consistent” with gunshot residue, containing two of the three elements associated with GSR.

As her evidence continued yesterday, she said the testing could not confirm how the particles came to be on the swabbed items or how long they had been there.

“There is no saying how these particles got to the location,” she said. “We cannot say how or why it got there. We can just tell you whether or not it is there.”

Given a series of examples, she said it was unlikely for a firearms officer to still have particles on him months after they last fired their weapon if they had washed their clothes, cleaned their weapon and bathed in the intervening time.

However, under cross-examination she confirmed that household cleaners would not destroy GSR particles, only move them.

“You would be essentially moving it on to a different surface or removing it from the surface,” she said. “You are not breaking down the particles.”

Ms Helsel similarly said that while a vacuum cleaner would likely pick up particles, they would be captured in the filter or the storage container.

Asked by Mr Richardson if the particles found on the tests carried out on November 4, 2017, could have been there before November 3, Ms Helsel confirmed it was possible.

“It’s not possible to determine when these particles got on the clothing,” she said.

Ms Helsel confirmed that some labs would not test hand swabs if they were taken too long after the shooting, but said the RJ Lee group did not have such a restriction.

“Ultimately, if the client wants it tested, we test it,” she said.

She told the court that she had taken a series of swabs in areas across the island for a study on GSR in the environment, but accepted that she did not test the custody area of the Hamilton Police Station or the inside of police vehicles.

Ms Helsel told the court that the areas tested were selected by the Bermuda Government to compare against a previous study.

She accepted that it would be useful to test in the police station and vehicles if the study was looking at potential contamination.

However, she was not aware of any study in Bermuda focused on that element.

The trial continues.

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