started Oct. 24. Gregory Bush, 51, having failed to get into a black church outside Louisville, went to a Kroger. There, telling a bystander that “whites don’t shoot whites,’’ he killed two black shoppers in cold blood.

Two days later, Cesar Sayoc, 56, was accused of mailing pipe bombs to a number of President Donald Trump’s political critics.

The next day, Robert Bowers, 46, invaded a Pittsburgh synagogue, shouted "All Jews must die!," and fatally shot 11 people.

Finally, on Nov. 2, Scott Beierle, a 40-year-old misogynist, shot two women to death in a Tallahassee yoga studio and then killed himself.

This type of hate criminal differs from one on which criminologists focused in the late 20th century: weekend haters — groups of young men who get their kicks and cement theirthe bathroom become the zealot who used the same phrase, with no irony, before invading a synagogue on a day of worship?

Bush was a diagnosed schizophrenic with paranoid delusions. Does that explain why someone who married an African-American later became so antagonistic toward blacks?

Beierle was a creepy bully of a substitute teacher who burdened students with extra work while he watched pornography on a classroom computer. But how did that lead to murder?

On the route to hate

Hate crimes reported to the FBI rose 17% last year, the third consecutive annual increase. And experts agree that such offenses are under-reported. Most jurisdictions responding to the FBI — including, absurdly, the greater Miami and Las Vegas police — reported no hate crimes in the previous year. Even the death of