1) The way our prison system works. It makes people worse. It makes them better criminals. It removes much of their opportunity to get better (try getting a decent job as a felon). It creates desperation. 2) the way we treat mental illness. By that I mean it is demonized and ignored. Does health insurance even cover mental health exams or treatments? Probably not basic coverage 3) Disparity of wealth. In the town I live in there are people living in absolute poverty and people driving around in lamborghinis and million dollar churches. The cost of that car could feed 50 people for a year.
In thiscase there is no telling what the root cause was yet. I suspect a case of someone just losing it.