[Update] My neighbor falsely believes my disabled BIL was being creepy, and I want to protect him. : legaladvice

Hi, all. Sorry for never replying to everybody's really kind, helpful advice -- I'm bad at reddit and really busy right now. I really do appreciate it.

For a few days after my initial post, my husband or I would walk my BIL to his usual spot after work and watch from a distance to make sure he wasn't behaving inappropriately (he might have by accident). Neither of us saw him do anything out of the ordinary; he just sat on the bench, took pictures, and looked around at the trees and flowers. He didn't watch or interact with anybody else, which is about what we expected. He's so, so shy.

Per a lot of advice, I didn't delete any of my BIL's photos for awhile. This pretty quickly got to be unmanageable though, because he takes 50-100 pictures every day, often just the same thing again and again. But we set up a google drive to save them all.

My husband and I also talked to BIL a LOT about what to do/say if he is approached by police. He is not very verbal and very quickly gets flustered and upset in unfamiliar social situations, so we really practiced pulling out his medical alert card and being very "non-threatening" with his body language (my BIL is 6'5" but has physical mannerisms a little bit like a child's, so if you don't know him or why he's behaving the way he is, he can be pretty alarming). To be honest, I'm still nervous about it, but we practiced and talked about it a lot.

As for my neighbor, I saw her again a few times and she ignored me. I considered bringing my BIL to meet her properly, but decided I didn't want to expose him to her freaking out. About a week ago, she approached me and told me she appreciated my "taking control of the situation," but that my BIL's disability was "no excuse." I said "No excuse for what?" and she said "for filming and photographing children." I considered pointing out that it isn't illegal to do that (as you guys did), but that would sound like he IS doing it, so I just told her that she isn't doing that. She threatened to call the cops again but so far nothing's come of it. I'm keeping an eye out. In any case, it's getting colder, and my BIL is spending less time just hanging out. He's also really happy to come with me to doctor's appointments, and I'm currently pregnant, so we've had a lot of those. (My neighbor started saying something about how I'd understand if I was a mother. I'm not showing yet, but I really considered telling her I was pregnant just to shut her up. But that's needlessly combative, lol.)

Thanks again to everyone's kind advice. Husband and I are currently working with BIL on responses he should give if that neighbor/anybody else approaches him while he's nature-photographing.

Oh, and thank you to the person in bestoflegaladvice who suggested a botanical garden -- we've driven to a few different ones now and it's really nice!! Thanks. :)