BOOK REVIEW : ‘Breaking Blue’ Cracks a Murder’s Silence : BREAKING BLUE <i> by Timothy Egan</i> ; Knopf $22, 263 pages

A tale of rogue cops and their acts of treachery and violence is told by newspaperman Timothy Egan in “Breaking Blue,” a story that reaches back more than half a century to an era when times were so hard that a man might kill over “a few pounds of stolen butter.”

Who killed Sheriff Conniff at the Newport Creamery in 1935? Who kept the killer’s secret for more than 50 years? A determined county sheriff named Tony Bamonte started asking these questions purely as a matter of academic research and ended up on a quest to crack “a conspiracy of small corruptions” that conceals a monstrous crime.

The clues uncovered by Bamonte’s belated investigation send us off in one direction and then another--a pair of pawned pants, a handful of shell casings, a missing .32 revolver that miraculously surfaces from the bottom of a river, the death of a rural sheriff who mysteriously falls off a bridge. The witnesses and the suspects, men and women who have survived into old age, are wrenched back into the distant past to confront their own secrets.

Egan presents Bamonte’s persistent quest for the truth as an assault on “the Blue Wall,” which he defines as “keeping a silence that is the bond of his profession.” Bamonte is a “hard nose,” a guy who refuses to “go along and get along,” and he dares to ask questions that have gotten other men killed. Bamonte pays a terrible price for his persistence, both personal and professional, but--in the end--his quest is rewarded with success. Thanks to Bamonte, the truth is out after half a century.

What Egan manages especially well--and what sets “Breaking Blue” apart from the glut of “true crime” books--is the evocation of the time and place in which the crime took place: the Pacific Northwest in the worst years of the Depression. If most true-crime books are dressed in the garb of psychodrama, “Breaking Blue” is hard-boiled social history--and that’s exactly why the book is so refreshing, so enlightening and so entertaining.

Egan gives us an intriguing portrait of Spokane in the ‘30s--”a town of cumbrous secrets,” as he puts it--and the profound social upheavals that turned cops into petty crooks and even killers. And he draws us back to more recent decades, when a county sheriff’s domain was still “one part Mayberry, one part backwoods dictatorship.”

We learn a new language of despair. A gun is a “smokepole.” A poor soul whom we would describe as “homeless” was known as “a bindle stiff,” and he might find shelter in a brewery-turned-flophouse known as the Hotel de Gink. A cop on the make, we discover, might spend his off-hours in the company of bootleggers and black-marketeers at an all-night diner called Mother’s Kitchen, a name that takes on dark irony as we discover what plans are hatched by the boys in the back.

Clearly, “Breaking Blue” has all the color, texture and detail of the most lurid detective fiction, and Egan makes good use of the material. But he is frequently tempted to turn a phrase, to pump the prose. Most of the time, he brings it off--but not always. For example, when Parsons, still an idealistic young rookie, earns a citation for police work, Egan tells us that he “wore the compliment like ranch initials engraved on cowhide”--whatever that means.

“Breaking Blue,” a morality tale of good cops and bad cops, is especially resonant in light of recent events in the courtrooms and streets of Los Angeles. Egan--and his protagonist, Tony Bamonte--remind us of the consequences of lawbreaking by those who are sworn to enforce the law, and they refuse to allow notions of honor and loyalty or the mere passage of time to conceal the ugly truth about a cop gone bad.

Tony Bamonte, who holds his fellow law enforcement officers to the highest standards of conduct, comes across as a man whose obsession amounts to an act of heroism. And Timothy Egan, who found the story and tells it so well, has succeeded in fulfilling the charge which Bamonte issued to his homicide detectives: “You are the voice of the dead.”