I'm a Gen X'r. From what I recall, things took a serious nosedive during the Reagan era. I'm actually pretty conservative about government spending. That said, I remember a time when we did not see mental health patients roaming the streets unable to care for themselves and/or committing these heinous mass murders. Because the more seriously mentally ill were, if not institutionalized, at least having their needs met on an outpatient basis at these same institutions. It also decreased the tremendous stress that is frequently placed on families who deal with very serious mental illness.
The last four or five paragraphs of this blog articulates it fairly well.
Ronald Reagan: The Bad and the Ugly - The Daily Nugget
p.s. Mental health care continued to roll back. In the late 80's working in psych, patients actually got a fairly long treatment time in residential care. Their families participated also, because frequently, changes in the family were necessary, not just in the person undergoing treatment. Now the patient may get two or three days in acute care. Mental illness simply no longer has ANY parity with other medical issues.
p.p.s. Even in years prior to that, though, there were incidents that involved people with serious mental health issues. For instance, Charles Whitman had a brain tumor. Now, that would have been difficult to foresee unless someone had prevailed upon him to seek care (as I gather that he himself noticed and wrote about the fact that something was wrong with him).
Richard Chase had schizophrenia. I believe that WAS known prior to his crime, but he was not receiving regular care.
But it does seem that now, with so many untreated/under treated individuals, the potential for psychotic episodes is much greater. And sometimes, these episodes will include violence.