Domanick’s hero, however, doesn’t show up until very late in the story. This is largely a book about how bad things were in Los Angeles before Bratton got there. Crime in Los Angeles had been increasing at twice the national average. Between 1980 and 2000, there were 11,500 gang-related homicides in Los Angeles County. “L.A.’s gangs were not simply growing but metastasizing.”

The city’s incompetent and brutal police functioned like “an army of occupation that waged war on the residents of black South L.A., Mexican East L.A. and Central American Pico-Union in the name of crime suppression.” During one operation, in South Los Angeles, 25,000 were arrested, though relatively few were charged with any crime. “It seems astounding,” Domanick writes, “that such a plan of concentrated, indiscriminate mass arrests would be executed in a major, liberal American city a quarter of a century into the post-civil-rights era.” Even the police dogs were out of control, surely a metaphor of some kind. Between 1989 and 1992, they bit 900 people, resulting in countless lawsuits.

Domanick is steeped in his city’s rich history, its fraught racial and ethnic conflicts and the complex demographics that befuddle so many outsiders. I lived there in the ’80s and ’90s, during recessions, earthquakes, the Rodney King beating and the ’92 riots: Domanick gets everything right. His brief portrait of the 1995 O.J. Simpson trial, for example, is a valuable corrective. O.J.’s lawyer Johnnie Cochran was no racial show boater, though the national media treated him like some sort of West Coast Al Sharpton. Cochran was a brilliant and highly respected local attorney who made his reputation trying police-abuse cases. “He knew what black jurors knew deep in their bones,” Domanick writes, “that racism, planting evidence, shading the truth and lying in court had been part of the Los Angeles Police Department’s modus operandi throughout its history.” The trial was always about the dysfunctional L.A.P.D., never O.J.

Validating Cochran, the decade climaxed with the infamous Rampart Division scandal. Officers were discovered to be routinely framing people, robbing and shooting them, planting evidence and stealing drugs. How long it had been going on or how many other units were involved, nobody ever knew. There was no in-depth probe. The department proved beyond a shadow of a doubt that it was incapable of policing itself.

Enter Bratton.

In a vivid scene at the Police Academy near Dodger Stadium, he read his new command staff the riot act. “He really chewed ass,” recalled Charlie Beck (then a captain, now Bratton’s successor as chief). “Going in and temporarily flooding areas isn’t what reduces crime,” an officer remembered Bratton telling them. “We’re not just a suppression force.” He moved decisively, demoting some top brass, forcing others into retirement. He brought in outside consultants, promoted whoever showed initiative. At first, his staff tried to control his movements and the flow of information to him, just as they had done with previous chiefs. That changed.