Is it illegal to follow a stalker?

I saw my stalker walking about 3 blocks from my house.  I turned my car around and drove behind him for about a block in order to get a better look at what he was holding in his hand.  I wanted to see if it was a weapon.  He noticed me.  Could he use this against me?

2021-04-07T16:02:12Z

I was going to the park with my dog to walk it because I can't walk it near my building because of him.  He's been visiting my building every day since December of 2020.  Also, he has given me death threats, both direct and indirect.

James2021-04-07T16:00:09Z

My thought is that it won't hold up in court if you can't explain the reasons why you had to do something. Why did you turn around and follow him instead of going home. It was to see if he had a weapon but why did you need to know. always always be able to explain yourself