Since 1993, America’s homicide rate has fallen by 40 percent. But in his impassioned new book, “Don’t Shoot,” David M. Kennedy notes that the crime epidemic hasn’t ebbed for everyone. Black men, he writes, are continuing to die “overwhelmingly by gunshot, at a horrendous pace.” And it’s getting worse. Between 2000 and 2007, the gun homicide rate of black men aged 14 to 17 went up 40 percent. For black men ages 18 to 24, it rose by 18 percent; for those ages 25 and older, it went up almost 27 percent.

Kennedy got his first look at the “the profoundly, indescribably, obscenely awful” things that go on in certain high-crime neighborhoods 25 years ago, at the Nickerson Gardens housing project in Los Angles. At the time he was a case writer at Harvard University’s Kennedy School of Government. (Today, he’s a professor at the John Jay College of Criminal Justice in New York City.) He was there to observe how the LAPD was responding to a terrifying new drug, crack.

“I’ve never been so scared in my life before or since,” writes Kennedy, recalling that day spent walking the thousand-unit housing project with two patrolmen. “My lizard hindbrain knew instantly that if they were somehow magicked away all that would be found of me would be my bleached bones.” (In fact, the dealers were scared of him: They thought he was a fed.) “People should not have to live like this,” he thought. “Somebody needs to do something.” Kennedy himself became that somebody.

“Don’t Shoot” is Kennedy’s account of his resulting career spent combating inner-city youth violence and drug markets. It’s an unorthodox book, part memoir, part polemic, with a spirit and style closer to “The Autobiography of Malcolm X” than to your typical book of wonkery. Like Malcolm X, Kennedy has no time for the pieties of the left or the right. To those who say that “crack sparked a ‘moral panic’: that it was never really that bad, that the public and political and law enforcement response was just a fevered overreaction,” he responds with a single choice expletive. Of the widely held opinion that America’s most dangerous communities and their residents are “uncaring, complicit, corrupt,” he says, “It’s wrong.”

To black communities who believe that crack was created by the government to destroy them, Kennedy says the same thing: “It’s all wrong. This is all wrong.”

‘Don't Shoot: One Man, A Street Fellowship, and the End of Violence in Inner-City America’ by David M. Kennedy (Bloomsbury USA)

What’s right is the solution — called Operation CeaseFire — that Kennedy and a group of police, probation officers and others developed in Boston in the mid-1990s. Instead of targeting gangs or drugs, the group targeted violence. It identified the most violent gangs and gang members, offered assistance and delivered a warning: If you start shooting, we will come after you. As an illustration of what would happen to gang members who ignored the message, police and prosecutors pointed to one particularly troublesome member of the Humboldt Raiders — “pretty much the city’s worst badass,” Freddie Cardoza. He was arrested with a single bullet in his pocket and got 15 years at a federal prison in upstate New York. The killing stopped.

Boston’s crime decline made Kennedy a star. In the years that followed, he took CeaseFire on the road. Some interventions worked. Others, such as one in Baltimore, were spectacular failures. Magazines such as Newsweek and the New Yorker lionized Kennedy. Academics rolled their eyes because his interventions were not randomized and his claims, they thought, were too sweeping.

“Don’t Shoot” is Kennedy’s response to his critics. It explains his successes and his failures. This is a book that names names. What saves it from score-settling solipsism is the author’s withering self-scrutiny. He writes of “starting to crumble at the edges” as Ceasefire interventions go national, of starting to carry a blade, of becoming addicted to sleeping pills.

As his story progresses, it becomes clear that “Don’t Shoot” is fundamentally a confession. As with every confession, the penitent changes. As the book and Kennedy’s career progress, he moves away from “hard” deterrence and begins to grapple with deeper issues, notably African American communities’ estrangement from a legal system that has become “an independent source of terrible damage.” “We are destroying the village in order to save it,” he concludes. “America has become a place where one in three black men will serve a felony prison sentence. One in nine between ages twenty and thirty-four is in prison right now.”

“We are systematically injuring one of America’s peoples. And we need to own that this is a choice that we are making. . . . We are doing this because we have decided to.”

No one who reads this gripping account of a life spent combating violence will doubt the truth of this statement.

John Buntin is the author of “LA Noir: The Struggle for the Soul of America’s Most Seductive City.” He covers law enforcement for Governing magazine.

DON’T SHOOT

One Man, a Street Fellowship, and the End of Violence in Inner-City America

By David M. Kennedy

Bloomsbury. 305 pp. $28