Why dont Police Finger print?

Im really beginning to think that Police are useless. My house was broken into 3 weeks ago and among cameras tv etc The criminals stole 2 ak-47's semi auto-matic and a military style SKS with an attached Grenade Launcher semi auto (32 round clip) I told them that Im the only perosn who lives here and they could finger print for other matches but they stated NO. I owuld think they would try to get these guns off the street as fast as possible.