Question

Police has not catch_____ the thief now. ( correct the sentence)

Answer 1

Police had not caught the thief till now

Answer 2

Here is the correct sentence :- Police has not caught the thief yet.    

As per the given sentence the police is searching for the thief from a very long time but they failed to find the thief and the police is still searching so I think Above mentioned answer is correct.

Here caught is a verb, police is a noun