Triple 9 Chiwetel Ejiofor, Casey Affleck, Anthony Mackie. Directed by John Hillcoat. Rated R. Opens Friday citywide.

Thriller Triple 9 begins with an exciting, superbly crafted heist sequence that recalls Michael Mann’s crime epic Heat, setting up expectations that the rest of the movie mostly fails to meet. A crew of highly trained robbers infiltrates a bank in downtown Atlanta, honing in on the single valuable item they need to steal and successfully intimidating and coercing employees without having to kill anyone. Then their getaway goes all wrong, leading to a tense car chase and standoff with police, from which the team barely escapes.

Director John Hillcoat (The Proposition, The Road) immediately grabs the audience’s attention with this sequence, and then has trouble holding it for most of the next 100 minutes. The members of the team, led by former military contractor Michael Atwood (Chiwetel Ejiofor), get bogged down in a plot for an even more complicated job, one that involves crew member Marcus Belmont (Anthony Mackie), a corrupt cop, setting up his straight-arrow partner (Casey Affleck) to get murdered by a disgruntled gang member, in order to serve as a distraction.

There are a lot of shifting alliances and double-crosses among the movie’s various cops and criminals, but despite a stacked cast (also including Woody Harrelson and Aaron Paul, plus Kate Winslet having a great time as an evil Russian mob boss), the characters are pretty thinly sketched, and Hillcoat and screenwriter Matt Cook misjudge which ones are the most interesting (the movie continues far too long after the best characters have been killed off). There’s another heist toward the end that demonstrates Hillcoat’s skills at orchestrating large-scale action and cross-cutting to build maximum suspense, and there are enough turns in the plot to sustain at least mild interest. Following the opening sequence, though, mild interest is the best the movie can manage.