My Mother Is Dating A Convicted Child Predator

Location: Ny

Hi reddit. Never thought I'd be doing this but here I am. I am 26f I live just down the road from my mother and 2 sisters. Youngest being 15 oldest being 21 and disabled. My mother is desperate to find someone to spend her days with as she's getting older and misses having a partner. She started talking to this man from Illinois and fell hard and fast. She has plans to move in with him next summer with my sisters in tow and I had a bad feeling about it from the start considering they've only been talking for a couple of months and are making such drastic life altering plans so quickly. So I decided to google this man for any info on him, and I found a link to how to catch a predator. He was charged on "criminal attempt to commit statutory rape" as well as "Criminal attempt to commit child molestation". I told my mother what I had found, and she sounded as though she was going to cut things off but he has somehow convinced her that it was 20 years ago so it means "nothing" that he's "a different man now" and she is choosing to believe him. he was convicted and served 4 years in prison with a 6-year probation. He has told her it got expunged because he was in the military. fan-fuckin-tastic. She still is planning on moving with my sisters by next summer if not sooner now that I am applying pressure for her to not do this. Is there literally anything I can do to keep my mother from making the single worst mistake of her life and endangering the welfare of my sisters?