It's a good idea to file a report with the police. That said, they won't do anything to help unless the guy physically attacks you. And unless minor children are involved, restraining orders are worthless.

Unfortunately, I've been in the situation and found out the hard way that law enforcement is useless when it comes to someone stalking or harassing you.

I feel for you, because the situation you're in is a very frightening one. Above all else, DO NOT accept ANY contact with the person or his friends.