Black Mass

NEW YORK  — The somber fact-based crime drama “Black Mass” (Warner Bros.), adapted from the eponymous book by Dick Lehr and Gerard O’Neill, chronicles the rise and fall of notorious Boston kingpin James “Whitey” Bulger.

Johnny Depp brings an intriguing blend of two-faced charm and menacing intensity to the central role. And the underlying values of this cautionary tale about the dangers of government collusion in wrongdoing are sound.

Yet, while the often harrowing bloodletting integral to director Scott Cooper’s film is generally surrounded with an appropriate sense of dread, a note of exploitative excess does creep in as the story progresses. Thus even those few moviegoers for whom it can be considered tolerable may ultimately judge this gritty journey through Beantown’s insular back streets offensive.

Joel Edgerton and Johnny Depp star in a scene from the movie "Black Mass." The Catholic News Service classification is L -- limited adult audience, films whose problematic content many adults would find troubling. The Motion Picture Association of A merica rating is R -- restricted. Under 17 requires accompanying parent or adult guardian. (CNS photo/Warner Bros.)

Joel Edgerton and Johnny Depp star in a scene from the movie “Black Mass.” The Catholic News Service classification is L — limited adult audience, films whose problematic content many adults would find troubling. The Motion Picture Association of A merica rating is R — restricted. Under 17 requires accompanying parent or adult guardian. (CNS photo/Warner Bros.)

Bulger’s story — which Cooper marshals to convey a resounding admonition against using illicit means to achieve valid ends — would be hard to credit if it weren’t true. Motivated by a misguided sense of ethnic and neighborhood loyalty, John Connolly (Joel Edgerton), a childhood acquaintance of Bulger’s in the Irish-American enclave of “Southie,” uses his position as an FBI agent to engineer a deal between the bureau and the initially small-time gangster.

According to the implicit terms of this corrupt bargain, Bulger will be given free rein to expand his underworld empire in exchange for information about his rivals in the Italian-American mafia.

For Connolly’s boss, Charles McGuire (Kevin Bacon), and his closest coworker, John Morris (David Harbour) — both of whom, despite some ethical misgivings at the start, become willing accessories to the arrangement — the goal seems a straightforward one: Use the small fry to catch the big fish. For Bulger himself, of course, it’s an obvious win-win: Use the feds to destroy your enemies, then take over their turf.

As Bulger’s uncontrollable barbarism causes events to spiral out of control, however, his rampaging ways threaten not only his G-men partners but his wily brother Billy (Benedict Cumberbatch) as well. An ostensibly respectable public figure who waltzes nimbly around his sibling’s shady reputation, Billy is a popular Massachusetts state senator. He’s also reputed to be the most powerful politician in the entire commonwealth.

Despite its indirectly religious title, and the unmistakably Catholic atmosphere in which its characters move, “Black Mass” devotes relatively little attention to faith.

We’re shown the fleeting image of a fatuous priest enjoying himself at a St. Patrick’s Day banquet where the Provisional IRA (to which Bulger has ties) is being praised. And Bulger sits silently in a church while brooding on his downfall. But otherwise religious expression is confined to the scenery.

So it’s not irreverence but rampant indifference to human life that may give even the heartiest ticket buyers pause.

The film contains frequent brutal violence with considerable gore, mature themes, including prostitution, about a dozen uses of profanity and pervasive rough and crude language. The Catholic News Service classification is L — limited adult audience, films whose problematic content many adults would find troubling. The Motion Picture Association of America rating is R — restricted. Under 17 requires accompanying parent or adult guardian.