where im at they are pretty accurate. i got locked up and put in county and during the processing they put about 30 of us in a cell and told us if we had anything take it out now and throw it on the ground, the dogs were gonna search us. Me, had coke all over the front of my jacket took it off and threw it on the floor and i'll be damned if that dog didnt smell it. went straight to it like he had a fucking radar...glad i took that son of a bitch off, no tellin what the dog would have done to me.