I will say this from a position of experience, never underestimate a deranged person's determination and ability. Stay vigilant and aware. We ended up with a 4k 360* camera system and fortunately have never had an issue since installing it back in 2010.
We had a renter, who, unknown to us is a schizophrenic, that went off his meds and went over the falls. He called my wife to inform her that Jesus had given him our house he was living in and as a result would no longer be paying rent. He also told her that Jesus had given him a 12g shotgun and if I attempted to evict him he would use it on us. Then, he took to wearing a ghillie suit and carrying the shotty around the neighborhood and hiding in the yards of neighbors. Sheriffs picked him up and placed him on a hold and we got him evicted. Sheriff told us that most people underestimate these guys as just "weird" or "looney" but rarely see the actual real threat they can be.
Again, stay vigilant