I'm not an attorney (although my mom is and my grandmother was a judge) and this is not legal advice....just one homeowner to another.
Consider this: If you now know everything about that evening and do nothing it could be argued (perhaps successfully) that you are tacitly OK with their visit. Now suppose one of the JWs, who might be uninsured, develops a back problem that supposedly occurred during his "visit" to your home?
It is a stretch but, might he sue you for his injury? If you think that is a stretch, think of the "attractive nuisance" laws. Think of robbers who are shot while committing the robbery who sue the person being robbed. There is an endless list of possibilities. Especially considering the animus that exists and the attempts to prevaricate
My only point is that you don't know what you don't know. Perhaps a report to the police without actually pressing charges would be a reasonable response.
Stranger things have happened. I would want to have an official record of what actually happened.