How would people under federal investigation for fraud, embezzlement, cyber crimes and identify theft be allowed to enter peoples homes with this site?

This isn't the proper forum for this post, plus there are no hyperlinks to the sites you tried to add to your post. If you have concerns please contact Rover support at [Edit: Rover’s contact options have changed. Visit the Rover Help Center at https://support.rover.com/ to find the phone number, help articles, or chat with the team]

This sounds like a personal issue with the sitter. If they are merely under investigation then that doesn’t mean they are criminals. If they don’t pass the background check anymore then they can’t be a sitter.