Research of this type is paramount in finding ways to reduce the negatives of gun ownership.  Congress has been incredibly myopic in refusing to fund research.  Just looking at this one report, potential future policy changes can be seen.  If crimes are being committed by lost guns, create liability for not taking sufficient care with your guns.  Another possible way to fix it would be to have gun owners annually present their guns in some way so that it can be determined if they are actually paying attention to their guns.  

Guns are made to kill.  It is crazy that in 60% of the time, the original gun owner did not know when the gun went missing.  That is extremely negligent.