In the end, what type of weapon you used is less important than whether you needed to defend yourself. I don't burden myself with a lot of "what if's". In Ohio, we recently got some improved legislation regarding defending one's self in the home. If it's an aggavated burglary, and the situation turns to one of the homeowner or resident mortally wounding an intruder, the law pretty clearly protects the resident. Knife, ball bat, SMG, shotgun, suppressed pistol. Not a big deal. Did you NEED to mortally engage the attacker? That's about it. Re silencer forensics: A really GOOD ballistics tech MIGHT have some knowledge about evidence relating to gunshots from silenced weapons, but about 99% of the techs around the country won't. A "dry" can will trap a lot of powder residue, disguising/altering the distance that the shot took place. A "wet" can will add addition crap to the scene or victim, in the form of semi-liquid coolant and suppressor crud being blown out with the projectile. The debris from the wet can would probably give techs something to examine and match to the silencer being used. A smart criminal would probably use a "disposable" suppressor made of PVC, and toss or burn it after use.