In "Wyatt Earp: A Vigilante Life" (Hill and Wang, 296 pages, $30), Andrew Isenberg, a professor at Temple University, calls on the big guns to debunk the Earp myth: German sociologist Max Weber, Henry James and even Shakespeare's Prince Hal. You may wonder exactly what these men have to do with the frontier West, and you may finish the book still wondering.

It's been more than half a century since anyone accepted the hagiographic version of Earp's life offered by Stuart Lake in the 1931 book "Frontier Marshal," but Isenberg insists on judging Earp on his Hollywood image. We've known for decades that Earp as a young man may have been involved in a horse theft, that he spent some time as an "enforcer" in a bordello, and that he went on a vendetta ride to avenge his brother's murder in Arizona.

The Vendetta Ride looms large in Isenberg's narrative since it was a classic example of the lawman taking the law into his own hands. The reader, though, might feel more sympathy for Earp than Isenberg intends, since Earp's only alternative was to let his brother's assassins go unpunished.

Isenberg cherry-picks through the historical record, discarding evidence that doesn't support his case. An example: In the famous 1896 controversy in which referee Earp stopped the heavyweight fight between "Ruby Bob" Fitzsimmons and Tom Sharkey and awarded the fight to Sharkey on a foul, Isenberg quotes only from the San Francisco Call, not the San Francisco Examiner, which supported Earp in his decision.

Unable to blame Earp for the gunfight in Tombstone — the historical evidence weighs too heavily on Earp's side — Isenberg decides that the killings were indirectly Wyatt's fault as "the consequences of his ambition," Earp's ambition apparently being the only one that mattered.

The most baffling assertion Isenberg makes is that there was some kind of homosexual relationship between Wyatt and Doc Holliday. The evidence for this is absurdly thin: Bat Masterson, in a magazine story on Earp, referred to Wyatt and Doc as Damon and Pythias, which had "a long-standing association in the English-speaking world with homosexuality." But Isenberg seems to think that frontiersmen of this era spoke in "coded" language.

"Wyatt Earp: A Vigilante Life" isn't really a biography, providing very little in the way of information on Earp's life. It reads more like a lawyer's indictment, coming down hard on his subject for not living up to his TV and movie white-knight image.

Allen Barra writes for American History magazine. His latest book is "Mickey and Willie: Mantle and Mays, the Parallel Lives of Baseball's Golden Age."