Get a security system with outdoor cameras and film the shit.
Video fucking works, everyone should have them in & around their houses and in their cars. I am getting a body cam to fucking wear. Too many times shit happens and it's just you and the other person, and you know they're lying and you WISH you filmed it.
Liars wilt and retreat when they know there is evidence.
Record everything. If they're into shit, they are dangerous. Do not take any chances. Think about moving out if you can't go to cops. Be stealthy and do not take them on. No shitbag is worth your life.