Should I just tell him no

My fiancé has a friend who is a criminal. The friend has been to jail for armed robbery twice and again for a felony with a gun in public place. I don’t want this person around our home or two children. My fiancé has known this person from when they was kids. They took different paths in life. We was at cedar point when my fiancé and him ran into each other and now he wants his friend to come by and catch up and grill. I know people change but I’d rather not have him at our home. I think they should maybe go to dinner or something and actually hang out before my fiancé brings him to our house where our kids lay they head. My fiancé also says he is a bit concerned because he did go to jail for robbery but he doesn’t believe he would rob him 🤷🏻‍♀️🙄. I just would rather be safe then come home to an empty house one day. Maybe I’m wrong. Am I wrong