Ciudad Juarez, Mexico, and Allegheny County have the same population -- about 1.2 million. Eighty-five homicides were recorded in Allegheny County last year. Juarez has had that many in a week.

The murder capital of North America, Juarez recorded a staggering 2,643 homicides in 2009. Few were investigated, much less solved. (Last week, seven police officers were gunned down at a busy Juarez intersection. No arrests have been made as yet.)

The murders and the hopelessness they have created in Juarez are almost impossible to fathom, even if you live just across the border in El Paso, Texas. A city of 640,000, El Paso had 13 murders last year, making it an oasis next to a slaughterhouse.

Charles Bowden ventured into Juarez regularly when the killings began to escalate in 2008. By popular explanation, Juarez exploded because the Sinaloa and Juarez drug cartels went to war.

Mr. Bowden challenges this conventional theory with a passage so crisp and clear that it resonates:

"There are two ways to lose your sanity in Juarez. One is to believe the violence results from a cartel war. The other is to claim to understand what is behind each murder."

But for every enlightening section of his book, Mr. Bowden seems to write two muddy ones. His prose can be as dense as a lawyer's brief, his storytelling as inefficient as the Juarez city detectives' bureau.

"Murder City" has other flaws. It is filled with jarring leaps back and forth through time. The author provides no index to help untangle messy sections. Anecdotes intended to give readers a sense of Juarez raise questions instead of answering them.

Still, after a hundred pages or so, sheer momentum takes over. What Mr. Bowden lacks in organization is to some extent offset by fresh details and writing that occasionally shines light on border life.

Even people who think they know the Juarez story well will find surprises and learn something from his reporting.

Part of the book's raw power comes from Mr. Bowden plowing into the obvious questions that always go unanswered. For instance, he writes that cocaine arrests are as rare as a peaceful night in Juarez.

Yet the cocaine industry's base and distribution points are an open secret. Everybody in town except the police and deputized soldiers knows at least a little about this part of the drug trade.

Cynicism is not limited to those sworn to uphold the law. He tells the story of a newspaper hawker shot to death on the street. Days of sorrow for the poor man were replaced by despair upon learning that his real job was selling drugs.

"Murder City" does not match the quality of Mr. Bowden's other border book, "Down by the River," about a murder in El Paso. He spent seven years reporting and writing it and his look at Juarez is thin by comparison.

But if nothing else, he makes his case that Juarez is dying as the political machinery sputters along at a safe distance, unable or unwilling to stop the bloodshed.

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