The typical mass murderer is extraordinarily ordinary.
We have made significant increases in providing shelters, hot lines and restraining orders to protect battered spouses and mandatory arrest for domestic violence incidents, ... And the largest beneficiaries have been men. The biggest drop is in women killing husbands.
We've had eight wonderful years of declining crime rates, and at a certain point you just can't push those numbers further down, and we've hit that point.
The Will to Kill: Making Sense of Senseless Murders.
The great successes we had a decade ago is gone. We let down our guard. The situation is not yet lost, but it could get much worse.
People in groups do things that they wouldn't do on their own. ... and certainly, once the idea is planted, it is easier to perpetuate.