I might need to report my neighborhood mechanic to the police
Why are you making such a sensitive decision?
He probably took something that doesn't belong to him.
You shouldn't report someone to the authorities unless you have good reason.  Make sure that whatever is missing actually was stolen, and not just lost, before you start blaming other people.
It's fine, I don't have to worry about it anymore. The item was just found.
That's great, but it's exactly why you should be certain someone did something before reporting them to the police. You wouldn't want to be responsible for an innocent person getting arrested.