DON'T I did this when I was in my 20's I thought I was being good I didn't think of us ever meeting but one day he showed up at my door, lucky my folks were not home and he continued to show up I tried to give I am too busy but he wouldn't let up a neighbor across the street saw and heard me trying to tell the guy I am not interested she got a hold of the guy and told him to bugger off and I was not interested.
BAD IDEA if he is a robber he could rob your place or a rapist he could.... he was in jail for a reason and true some reform but I feel it is rare I was lucky nothing happen from this guy but IT COULD OF and you can't be to careful these days
You best to write to a military person it would be a GOOD THING TO DO
here is the link
you have to become a memebr I think but there are plenty here you can write to.