"I'm saying it's far more likely for crime to be caused by factors other than mental illness due to the fact mental illness is not that common. A lot of bad decisions are behind criminal behaviour, but sane people don't try to kill random individuals. Sane people also prefer to avoid drawing attention to their criminal activity. Killing people draws attention to your criminal activity."
All those things are true, and I'd agree with them. But, again, you're making assumpitions. Stats show that MOST home invasion (and most violent crime) occur at night. So, you're awoken by the sounds of a forced entry into your home, it's dark, you're disoriented, you're scared, you know you want to get to your little daughter's room to make sure she's ok. Now, you're throwing in trying to make an assessment of whether or not the guy in your home is sane or insane, sober, or on drugs, and whether any of these factors is going to make him want to do harm to you or your family. To me, that is INSANE.