Black Mass tastes like Oscar bait, with a sort of comeback to form by Johnny Depp. While most are lauding his accomplishment as a (long-awaited) step up from his candy-coated Tim Burton performances, to me his take on Whitey Bulger was like another costume that he slipped on like a second skin. Depp's performance is certainly worthy of an Oscar nomination, and you never doubt who he's supposed to be. The problem here is, and with the whole movie, is that his character never seems quite natural. For a story that is supposedly true, it's on the whole less believable than the old gangster epics we grew up with like The Godfather and Goodfellas.
Part of the problem lies with the narration: the story is supposedly moved along by informants or close friends of Whitey only to easily sinuate into scenes and situations they wouldn't know to tell. We're told more than we're shown the complexities of Whitey's character and the plot points that are meant to accentuate his hardening of character seem too carefully placed and isolated to really give any flow to a film that unfortunately lacks momentum. And there's so much depth that we could plumb and elude to, such as Whitey's relationship to his brother, Billy Bulger the Bostonian senator. Instead, the movie seems far more concerned with the increasingly paranoid and violent persona of Whitey, which hardly seems necessary to focus more than a couple scenes on. Indeed, some conversations and scenes run on far too long, forcing us to see who Whitey is rather than allowing the chill of Depp's performance linger in our bones unbeknownst until later.
It is a phenomenal ensemble performance, however. Some of the Bostonian accents suffer (Good Will Hunting did it better), but Depp is probably the primary reason to see the movie. Joel Edgerton also does a great turn as Whitey's old friend in the FBI who spirals into a sycophantic lugubrious henchman with a badge. It's not Cooper's best work, but he services Depp well enough and there are a few interesting slow zoom-ins to reflect Whitey's paranoia and relational dynamics. Other than Depp however, the movie is generally forgettable and not necessarily justified for a theatrical viewing.