[aimhigh]

I’m confused. Since the perp was shot at, wouldn’t that shot put residue on him?

[exit82]

The perp fired three shots at the off duty officer. So the residue is from the perp’s gun.

That is more forensic evidence that he not had a gun, but that he fired a gun.

[tacticalogic]

I’m confused. Since the perp was shot at, wouldn’t that shot put residue on him?

Gunshot residue is the leftover residue from the gunpowder igniting. You have to be within a few feet of the gun when it's fired to get any on you. The perp was shot from too far away to have gotten any residue from the officer's gun on him.