Paranoid Neighbor Harassing & Making Up Accusations - How To Protect Ourselves?

Texas, USA.

I’m worried about my parents’ neighbor and his strange paranoid behavior and thinking toward them.

Parents are 65+ years old quiet adults in the suburbs who never have anyone over or act disruptively. Neighbor and wife moved in a couple years ago, wife has never really been seen, but Neighbor has consistently acted really weirdly in a way that’s concerning.

Neighbor has decided that someone is coming into his backyard to smoke cigarettes under his window at all hours of the night - potentially “local teens” (again they’re way out in the nearly-rural burbs, not exactly a youth hangout hotspot) but mostly focused on my dad, who does smoke - but only on his own patio, dozens of yards from their house, and certainly not all through the wee hours as Neighbor claims (he goes to bed normally and doesn’t get up in the night).

Neighbor has repeatedly sent them long texts accusing dad of waking him up at all hours with smoking smells, and imploring my mom to make him confess. He has progressed to sending these texts even throughout the wee hours claiming that my dad must be currently standing in Neighbor’s yard smoking, when in fact my dad is in bed bc it’s 1am.

He claims he has correspondence from the previous homeowner that they smoke at all hours (but has never shown it). He has cameras all over his own yard and incidentally touching theirs, which haven’t caught anything (ofc bc it’s not happening), but he believes his own paranoia over the video evidence.

He also just recently put up a camera pointing directly into their backyard, ignored my dad calling to him while he was putting it up, ran away, then when asked over text said he didn’t know what they’re talking about, took it down immediately, said it was a spotlight instead of a camera, and other lies. So I think he’s weird enough to believe the smoking stuff but sane enough to try to cover his tracks.

Neighbor has also apparently boasted to them about his long military career, including an incident where he (surprise!) was being woken up all night by cigarette smoke, so he knew that teens were sneaking in (to a US military base mind you), and all his colleagues made fun and called him “camera guy” for setting up surveillance, until (according to him) he supposedly caught them and proved to everyone he was right. To him this seems to prove how right he is, like he’s followed in life by a series of mystery ghost smokers, rather than him being the common link in these stories.

Any legal advice? He hasn’t threatened them directly but this feels like harassment and it’s escalating. I’m worried that he is detached from reality and will continue to bother them, make false accusations, or worst case scenario try to retaliate in some way.