Non Lethal Self Protection Advice

[awsmith4]

Recently my inlaws were having issues with a deranged neighbor coming on to their property at night and vandalizing random things as well as petty theft. After numerous incidents they installed a camera system. Well this oh so bright individual tried to steal one of the cameras and even pointed it at his face while pulling it off the wall of the garage. He was arrested the next morning and is still sitting in jail because no one will bail him out...

Well after the arrest they learned more about this individual and he has quite a rap sheet, mostly assault. Most of those assaults were on former neighbors (he moves around a lot). Turns out he has some sort of mental disorder and is not a likely person to learn his lesson while in prison. So if he were released there is chance he would retaliate.

They own guns but my mother in law isn't sure she wants to have to carry in here own yard but feels she would carry a taser or something else that is non lethal and wants something for when she is home alone. She says she is not sure she could bring herself to shoot and kill.

So my question is what would be the asylum's advise for non lethal protection?