Mr. Lankford saw Townsend’s goal as “racial peace in troubled Birmingham,” and believed that it was being served by the surveillance he conducted in frequent concert with the police. Indeed their mission was aided by a previously undisclosed communitywide network.

The phone company gave Mr. Lankford and his law-enforcement cohorts spiked pole climbers and instructions on “running” various junction boxes, and lent them an old truck still bearing the Southern Bell logo.

A local rabbi — one of the eight clergymen to whom King addressed his “Letter From Birmingham Jail” — purchased spy equipment for the police, intending for it to be used on racist groups under investigation for placing dynamite at a local temple in 1958.

But the electronics also ended up being used on white community leaders and, naturally, the civil rights movement. Mr. Lankford says he and a police detective even eavesdropped on union officials representing Newhouse’s broadcast employees during contract negotiations. One popular wiretap target was a local pastor, A. D. King, who was overheard arranging a rendezvous for him and his visiting older brother, Martin Luther King, with women who were not their wives. The police organized a sting, with Mr. Lankford along to take pictures. We may never know if the intelligence on the brothers was correct, because the detectives lost the car carrying the elder King that night in a traffic jam.

But the most surprising detail about this incident is that it happened in October 1963, months after Connor was forced from office. That means that the new, supposedly enlightened city government was carrying on his battle to destroy the movement that had just irrevocably put Birmingham on the map, next to Gettysburg: those “events of Birmingham” had moved John F. Kennedy to introduce what became the Civil Rights Act of 1964.

As its yearlong commemoration of those events now begins, white Birmingham will be tempted to fall back on its favorite “Bull Connor as bad apple” defense. Even for those who lived through segregation, it’s hard to accept the civic truth of Shuttlesworth’s time: that “racial peace” was an objective supported by murder.

“Everyone behaves badly — given the chance,” Hemingway wrote in “The Sun Also Rises.” What sets white Southerners apart is that they had so many ways to go wrong, confronting a moral dilemma each time they drank from a white water fountain. Painting all segregationists as cartoon racists encourages the rest of us to take cover under a blanket illusion of blamelessness — give or take an Abu Ghraib or a Penn State football program. Or the F.B.I.’s own obscene wiretap campaign to discredit Martin Luther King.

If I were to indulge in the annual “If King were alive ...” game, I would guess he’d be morally embarrassing the insidious new “normal” — assassination by drone, for example, and the repressed torture “debate” that has returned on such a timely holiday. Do we really want to be a country that argues about whether torture “works”? So did segregation.