All the hoopla around the Simpson trial reveals nothing about O.J.’s guilt or innocence, but it does show the intensely different ways that Americans perceive the police. For many African-Americans in L.A. and elsewhere, policedom itself is so suspect as to be a hindrance to real justice, and so institutionally racist as to be an untrustworthy source of evidence. But for white Angelenos and those less likely to be victimized by the police, recurrent violence can be overlooked in the quest for order. That we live in an increasingly dangerous world is obvious. How we react to it depends largely on race and class—that is, how we relate to police.

In his timely Edge of the Knife: Police Violence in the Americas, Paul Chevigny examines police brutality in New York, Los Angeles, São Paulo, Buenos Aires, Mexico City, and Kingston, Jamaica. Each of these six cities belongs to the U.N., subscribes to the Convention Against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, and claims to adhere to the same basic principle of human rights. Yet their records vary widely. Some of the worst police abuses occur within Latino societies, so a superficial overview might attribute the violence to cultural differences. But Chevigny disputes this notion with studies of Kingston and Mexico City. Rooted in British colonialism, not Iberian conquest, Kingston boasts one of the Americas’ most violent forces, while Mexico City claims a corrupt but considerably less brutal force.

Chevigny, a New York University law professor, has covered law-enforcement turf before, in his 1965 study Police Power: Police Abuses in New York City and in Cops and Rebels: A Study of Provocation. He devotes a large portion of Knife to patterns of abuse within the two U.S. police departments, and focuses on their bureaucratic structures and the sociopolitical climates in which they work. Through eyewitness accounts, interviews with inside sources, and external fact-finding, he assembles a disturbing portrait of brutality.

The NYPD, one of the more effective systems in Chevigny’s estimation, has a centralized and entrenched bureaucracy. Every time a weapon is discharged, elaborate documentation procedures must be followed—which tends to minimize excessive shootings but maximize efforts to cover up any real abuse of power. When the force comes under intense journalistic scrutiny, officers are instructed not to discuss incidents with the press, and police ranks close quickly to prevent scandals. Although the NYPD sometimes turns a blind eye to corruption charges, Chevigny writes, strict internal controls leave the force with a relatively good record on violence.

The LAPD, on the other hand, was created along military lines in what not so long ago was a frontier state. Chevigny reports that a siege mentality still prevails, and extreme measures against suspected criminals are tacitly condoned, if not encouraged. L.A. police chiefs hold civil office, which supposedly removes them from the political sphere but actually allows them to impose their own agendas on the guardianship of the city. Since the ’50s, this has meant a force that takes pride in its hard-nosed approach and doesn’t hesitate to establish control at the expense of civil or human rights.

Tough talk and tough action are different things, however, and Chevigny digs hard to find numbers on the LAPD’s violent deeds. He compares records for civilian deaths at the hands of police with police deaths at the hands of civilians, and dredges up the accounting on damages paid out as a result of police-related brutality cases. Like any historian, he crunches numbers and traces the great shape from the tiny details.

In Latin America, this kind of legwork is more difficult due to a lack of hard evidence. So Chevigny turns to the players themselves to flesh out the picture, drawing data from interviews with police, attorneys, and journalists. He finds that São Paulo’s militaristic police structure and vast economic disparity are a volatile mix; in their efforts to control and intimidate Brazil’s underclass, the “P.M.’’—beat cops who patrol and make arrests—routinely fire on fleeing suspects, and later fire into their own patrol cars as proof that they’ve been through shootouts. According to the author, São Paulo’s enforcers also make frequent use of an interrogation method known as “the parrot’s perch,” in which a suspect hangs upside-down by the knees while answering questions or being given electrical shocks. What’s most remarkable about Chevigny’s findings is the perpetrators’ willingness to implicate themselves (at least indirectly) in acts they do not view as illegal: One chart, proudly constructed for the author by a senior officer of the P.M., shows that the police were accountable for nearly 20 percent of all homicides in the city in 1991-92. Such alarming firsthand data propels this chilling but compelling read.

Nevertheless, Knife’s accounts of institutional kidnapping, torture, and murder threaten to inure readers to violence. The book’s litany of numbers sometimes obscures the passion and compassion that obviously inspire Chevigny’s research. But the author does not simply document horrors. He makes a point of analyzing methods by which abuse might be restrained: legislation, punishment, monitoring, and reform. Throughout Knife, he argues that the military model for police work ensures a confrontational relationship between law enforcement and civilians; as an alternative, he advocates a more responsive civil model, with particular safeguards.

A contributor to Americas Watch human rights reports, Chevigny is an unsurprising advocate of external, international monitoring. He also asserts, using the six cities at hand, that only a strong national commitment to human rights monitoring, both at home and abroad, can provide the proper atmosphere for reform. Finally, he writes that reform within the police force—instituted from the top down—can bring real change. Police work by nature relies on the discretion of officers in the field, and if officers guilty of brutality are disciplined, a nonviolent message is quickly spread.

Despite his confidence in the possibility of change, Chevigny acknowledges that real reform is a tall order. Political climates, citizen pressure, and economic change all affect the process. Yet, for those who strive for a more equitable world, Chevigny’s careful study at least provides a rough framework for action.CP