“Detained” is a bloody-minded thriller of “The Usual Suspects” variety. There’s a crime scene with a lot of bodies, and somebody is going to need to explain how they got there, preferably in a series of long flashbacks.

That’s the aim, anyway. But think of this Felipe Mucci (“Two Deaths of Henry Baker”) film, with limited sets and a fixed number of characters, as a play — a play that needed further workshopping.

Abbie Cornish stars in a woman who wakes up in police custody. She blacked out, the cops (Moon Bloodgood, Laz Alonzo) tell her. Somebody’s blood is on her car bumper. She can claim the bar pick-up she met (John Patrick Amedori) “roofied” her, but bad cop/worse cop aren’t buying it, even if they’re up to hearing it.

“Why don’t you walk me through it?”

She’s a woman of means, so she wants a lawyer. But who IS this green kid (Justin H, Min) who shows, unbidden, up in a suit with a briefcase?

What’s the deal with this “precinct,” the fresh paint she touched in the bathroom, the dangerous, unsupervised drunk tank with the deranged “Sully” (Silas Weir Mitchell)?

And that opening “crime scene” aftermath?

Actually, that unnecessary opening simply establishes how clumsy the structure of this script is. The film’s true beginning that is “flashback,” with Rebecca Kamen trying to figure out how she got here, what’s going on and what cards she has to play in this mouse and two-cats interrogation.

Cornish plays our “heroine” as puzzled but cagey, wary and curious. “How did I get here?” is just the first question.

When her besty (Breeda Wool) shows up, she takes a hasty bite of what looks like a Nestle’s CRUNCH Bar. Sarah then covers the letters on the wrapping as a warning to Rebecca.

“RUN.”

That’s clever.

And there’s enough going on here to hold one’s interest…up to a point. The ensemble is believable enough in their respective roles and the violence ranges from depressing to jolting to furious.

It’s the “what’s going on here” that becomes too convoluted to invest in, killing the pacing and robbing the suspense of any sense of urgency. The escalations and rising violence and body count utterly botch any sense of mystery about each “usual suspect,” and that shred of promise Cornish & Co. give the picture in her opening moments is lost.

Rating: unrated, graphic violence

Cast: Abbie Cornish, Laz Alonzo, Moon Bloodgood, Justin H. Min, Breeda Wool, Silas Weir Mitchell, John Patrick Amedori and Josefine Lindegaard

Credits: Directed by Felipe Mucci, scripted by Felipe Mucci and Jeremy Palmer. A Quiver release.

Running time: 1:37