NSW Police homicide squad detective inspector Wayne Hayes told the inquiry test swabs on the 9mm pistol revealed DNA from another, unknown, person on the gun’s trigger, slide and grip.
Det Insp Hayes said he would like to fly to Baghdad as soon as possible to take voluntary DNA samples from Pte Kovco’s two roommates, who were with him when he was shot on April 21 this year.
The inquiry has heard previously that the two roommates were in the tiny barracks they shared with Pte Kovco when the gun went off.
However, they have both told the inquiry they did not see the gun discharge.
Det Insp Hayes said DNA tests had already been carried out on military police and NSW police officers who had handled the gun with gloves on, but none of their genetic material was found on the weapon.
He said it was possible that other soldiers could have unknowingly touched the gun after the shooting while they were trying to save Pte Kovco’s life, or that they dripped perspiration onto the gun.
Another possibility was that Pte Kovco’s two roommates handled the gun when they were allowed back into the room to collect some of their belongings, he said.
Det Insp Hayes said based on photographs of the shooting scene, it was clear the gun had been moved at some stage.
He said that while there could be up to 30 soldiers needing to be DNA tested, he believed priority should be given to Pte Kovco’s roommates and two other soldiers, none of whom can be named.
The test would probably take a maximum of two days, with swabs being sent back to Australia for analysis and results produced within two weeks, he said.