What should i do about this?

Well, one of our family members who we didn't really know moved into our house and we already want him gone because we found out that he had criminal records. The problem is that my mom and I live by ourselves right now so its quite scary having a criminal at your house! We want to ask him to move out in a VERY nice way because we don't want him to act against us and try to hurt us because he has anger issues! Please help.. Any suggestions on how to ask him to leave without him hurting us?