For your own peace of mind have the freind in the police check him out for you. If there is something at least you can tell her and if not you can feel that you have done what you could.
Side note here "boy crazy " could have something to do with the previous problem she needs to see a councialor. If not here behavior could be picked by here 3 daughters. I have a freind that now relizes that it caused the problems for her 5 grown daughterss. Thankfully they are all going for help.