Bryant Tennelle was shot dead on May 11, 2007, as he walked with a friend down the south side of West 80th Street in South Central Los Angeles. He was an 18-year-old black man, just recently graduated from high school, and he was wearing the wrong hat.

Tennelle’s murder was one of 845 that year in Los Angeles, most of them concentrated in a few neighborhoods and many of which involved black men shooting other black men. It’s a pattern of violent crime that pockmarks urban areas across the country, particularly in the South. In the United States, black men make up only about 6 percent of the population but are almost 40 percent of those murdered, the overwhelming majority by other black men.

Jill Leovy’s Ghettoside: A True Story of Murder in America, tells the story of the police investigation of Tennelle’s murder and uses it as a jumping-off point to explore the seemingly endemic high rates of black-on-black homicide in South Central. A journalist at the Los Angeles Times, Leovy was embedded in the Los Angeles Police Department’s 77th Street Division starting in 2002. Her book is as important as it is difficult, especially now.

In the United States, the conviction rate for intraracial homicide involving black men is shockingly low. In South Central, witnesses’ fears of retribution, violence, and distrust of the police and the judicial system make solving these crimes especially difficult. Leovy notes that in the early 1990s, the conviction rate for homicide in Los Angeles County was just 36 percent. Like so many others, Tennelle’s case initially went cold, too.

Ghettoside details the working lives of a number of remarkably dedicated homicide detectives in the 77th, which covers South Central. Leovy describes their work as a “craft.” “They have very strong opinions about who’s good and who’s bad and what good work is and what bad work is and what the standard of craftsmanship should be,” she says. Some four months after he was shot dead—and his case increasingly unlikely to be solved—Tennelle’s case found its way to Detective John Skaggs.

Skaggs, himself the son of a Long Beach homicide detective, is the star of the book. A hardworking perfectionist, he considered a case clear rate of over 80 percent to be respectable, even disdainfully referring to other detectives as “forty percenters.” When he was tapped to become a homicide detective in the LAPD, his father had only one thing to say about it: “Be careful,” he told his son. “Because nothing else matters after working murders.”

The story is reported largely from the point of view of the police investigation and focuses on Skaggs’ uncanny ability to bulldoze his way forward until a seemingly dead-end case opens up. Leovy focuses on the facts—on the events leading up to and following the murder, on the backgrounds of the police and the victim and his family. She is a reporter, and she reports what she sees. But the facts invariably lead the reader to reflect on issues of race, justice and inequality, which it almost goes without saying are deeply contentious.

Which is why they are worth discussing. Leovy notes in her introduction that when former LAPD Chief William Parker pointed out that “black neighborhoods suffered higher levels of crime, liberals condemned him on the grounds that merely making such a statement was ‘inflammatory.’ ” And she writes, “The topic is, for many black people, one that inflames an abiding sense of vulnerability that lurks at the edge of consciousness.…Why emphasize what seems sure to be used against them?”

Throughout the book, Leovy returns to her central observation that “the state’s inability to catch and punish even a bare majority of murderers in black enclaves such as Watts was itself a root cause of violence,” that “the system’ s failure to catch killers effectively made black lives cheap.”

“Violence is different,” she says. The high rate of black-on-black homicide—that of violence itself—becomes a system unto itself, like that of the rule of law. In her words, “lawlessness is its own kind of order.” And, left unchecked, this violence becomes self-sustaining. “This book is about a very simple idea: where the criminal justice system fails to respond vigorously to violent injury and death, homicide becomes endemic,” she writes.

What necessarily follows is Leovy’s argument for the importance of bringing homicide offenders quickly to justice; by doing so, the state demonstrates to its citizens that it values their lives. At the same time, Leovy is critical of other proactive police work, often policies handed down from higher echelons of the force, such as having squad cars drive around with their lights flashing just to indicate their presence. “The LAPD is so vast and so complex that you almost can’t be on the street and in the higher echelons at the same time, and there’s a great distance between the two,” she says.

While events of the past few months have called simple prescriptions for police work into doubt, there are no easy answers here, either. Leovy doesn’t set out to offer them. It’s easy to step on toes when no less than people’s lives are at stake, and Leovy focuses on telling her story, painting a portrait of a community and a handful of dedicated cops, the value of whom she argues is underappreciated. “I never think of myself as a nonfiction writer. I don’t even think of myself as a writer,” she says. “I think of myself as a homicide person. That’s my thing. I’ve just been into homicide.”

Leovy’s expertise on the subject allows her to make arguments that run against the grain. “If you punish all sorts of things other than violence, there’s no credibility to the system,” she says. She writes in Ghettoside that “to assert that black Americans suffer from too little application of the law, not too much, seems at odds with common perception.” The American criminal justice system “hauls masses of black men through its machinery but fails to protect them from bodily injury and death. It is at once oppressive and inadequate.”

Walter Heymann is a freelance writer and screenwriter who lives in Los Angeles.