Harrick's right, Griz. This transfer is from Acey Nubs' lower-left hand, and it's positioned like he was bracing the gun while firing.
Unfortunately, there's no matching burn on the late mister Nubs. All three of the hands we have from him are unburnt.
Any nanomeds in his system? Maybe the burns healed post-mortem.
Guys, we've had it all wrong the whole time. There's a much simpler answer.
Our victim was killed by his clone, and we've got the clone's right hand on ice.
It's a bad week when clonicide is the simple answer.