My girlfriend has 2 children, ages 6 and 8. The reason my girlfriend and this guy split up is too much abuse on his part due to drug habits. The father has not been in their lives for almost 4 years now. Through a protection from abuse order, he had weekly visitation once a week from 12-6 pm. He would call around 3 and say he could not handle both and they needed picked up. Then he only wanted one at a time, and soon he just quit coming. Now he is basically stalking where we live to see them and grab to take them some place. My question is what is the best way to approach this so that he can't get them and hurt them again.

Hire an attorney, prove he is a threat to the children, get any visit by supervision though a court approved agency only