In my state this is not a theft because he is your tenant and yo
I was informed by cops that I had to sue them in civil court...
By the same reason, if somebody pulls a gun or knife on you, and demands you to give him the car keys, and then drives away, this is not a car-theft, but an "unauthorized use of vehicle", because you give him the key...
Qiaoshe, take it easy, go home and watch some Clint Eastwood with .375 Magnum.