What Can I Do If My Neighbor Is Constantly Fighting Her Mom's Tenant - Screaming, Throwing Objects At Him, Smashing Parts Of His Car?

For 7 years, my family has lived in a reasonable middle class non-HOA neighborhood in a small suburb. The house next door is owned by an elderly woman who is disabled (diabetic, low vision, amputee) who's husband passed away a few years ago. For the last 12-18 months the elderly woman's late-20s daughter has lived there as well as a late-20s male who may be the ex-boyfriend of the daughter. The house has an attached garage that seems to have been converted into a partial apartment with its own entrance. Our lots are around .4 acres and there is about 25 or 30 feet between the houses.

For the last year-ish, the daughter has regularly gotten into fights with the male tenant. These are almost exclusively one sided, where she is clearly the aggressor. She screams at him, often loudly repeating childish taunts and slurs over and over. Over the last few months she's thrown things at him or his car multiple times and smashed his car windshield and headlights. One time she threw a small, heavy, metal solar light at his car, which bounced off the car and flew to the far edge of the other side of my yard. At a slightly different angle it could have gone through the window into my child's bedroom, it's a dense little metal light (the kind you put on steps to a deck or patio) and was thrown very hard. Recently she's noticed when my wife has been working in the yard and screamed at him about being a pedophile. (She has elementary school age children in the home).

We know from hearing the young man's name screamed that he's been arrested for opioid related crimes and was a former cop in a different town over an hour away before that. The elderly woman was arrested several years ago but we don't know why and she didn't appear to serve any time. It was just after the husband died; I assumed it was minor drug related.

I have a security camera setup due to my work involving regular FedEx drop offs. The camera covering my driveway captures most of these incidents (with clear audio usually). I save clips that involve thrown objects or other physicality.

So far, we haven't called the police when they fight, although other neighbors on our street have done so. The police usually talk to the daughter and she gives them a sob story about wanting him to leave and he's done such horrible things. The cops leave and nothing changes. Things seem to be escalating toward direct harm, and we are concerned about the collateral damage to our property and children, as well as the children who live in that home. Without an HOA to enforce fines for the noise and litter, what can we do?