Originally Posted by Nightshade

No matter how you look at it a gun can be traced back to you at ome point or another.

The gun at one point was sold legally and from there some guy sold it to another and so on. Somewhere in there someone knows who they sold it to and it can be tracked that way. Once a gun is used in a crime the last known owner of that weapon is tracked down. You being the owner of that weapon with no bill of sale saying you no longer own it makes you responsible fo letting that person use your gun on a murderous rampage and will face some sort of legal aspect from it.