restraining order, gun, cell phone (and keep it on you at all times) the restraining order is of course the first defense... the cell phone to enforce it... the second anything happens, train that gun on him, and call the cops on the cell phone... even if you are eventually aquitted of murder, or the police rule i tself defense, there is ALOT of stress and shit in between.... best thing imo, to avoid all of this... is to get him back in prison... the goal of course is to have him break the restraining order, so he's sentenced back ot prison, safely away from everyone innocent...

as for what kinda gun, you don' tneed much (unless he's into PCP, even crackheads drop after a shot or two... but for some reason, PCP seems to make people completely immune to pain, and even worse, makes them superman.... check the stories for yoruself if you don't believe me... there've been stories where some guy gets a whole clip in him and just keeps coming) just get a 9MM, unless he's into pcp as mentioned, you might wanna invest in something with a little more stopping power... a .45 or shotgun should do...

kiling someone, even in self defense will more than likely weigh on your conscience for a long time (i haven't done it, but i can imagine how terrifying it would be..) not to mention what i stated above, the stress of the investigation (And there will be one, even if everything appears 100% legit) so you should really, try to get him back in prison or mental institution...

i dunno how things work up there, but down here it only takes a few family members to commit someone... have you considered this?