“The Loft” is a stylish whodunit that struggles to stitch the label “Hitchcockian” right on the inner pocket, where it would be on a man’s sports coat. But a quick glance down at that label, underneath the pulsating violins, the supposedly twisty plot and the convenient apartment full of suspects, reveals it’s just a cheap knock-off, probably misspelled to boot — “Hitchcopying.”

It’s about five upper-income-bracket pals who share a loft — not to live in, but for their assignations. It’s where these married men bring their “mistresses, girlfriends, one-night-stands” or, as a cop asking questions about it puts it, their “catch of the day.”

The reason there are cops (Kristin Lehman, Robert Wisdom) asking questions is the discovery of a naked dead blonde handcuffed to the bed. And the guys? They were the only ones with a key to the place, the only ones who know the security code of the alarm system.

Erik Van Looy’s film is a series of two-on-one interrogations, the police trying to make Vincent (Karl Urban), the womanizing architect who designed the building, or Chris (James Marsden), a pricey shrink, the bookish Luke (Wentworth Miller), slovenly Marty (Eric Stonestreet) or unstable coke-head Phillip (Matthias Schoenaerts) confess.

Not that every suspect is treated with equal suspicion. One of the problems here is that the police point their fingers at a couple of faces early on and the movie’s stumbling attempts to divert attention away from them.

Flashbacks show the marriages, the origins of the loft and the smirking way Vincent presents his “present” to his pals. Urban (“Star Trek”) puts on his best lady-killer leer for this one, while Marsden gets to do lovesick (again) and Miller (“Prison Break”) is cast as another quiet type who seems to harbor darker potential.

The womenfolk here are reduced to simple clotheshorses to be feared (the wives, led by an unsmiling Rhona Mitra) or desired. Rachel Taylor plays the bombshell who turns the shrink’s head.

The script by Wesley Strick (“Cape Fear,” “Arachnophobia”) has gaps that no multitude of hazy-filtered sex scenes or tension turning extreme close-ups can paper over. People know things they shouldn’t, or don’t know things they should. And by the time we’ve left the interrogation room, left the flashback to when the guys try to figure out, themselves, who did it before the cops arrive, it all sort of comes apart in an orgy of clumsy over-explanation that doesn’t truly explain anything.

But the quintet is well-cast, Urban is swell, the darkly-menacing Schoenaerts (“The Drop”) provides some fireworks and the old-fashioned theatricality of it might appeal to some — even Hitchcock himself. But characters we don’t care about, suspense we don’t feel? The Master of Suspense would hardly let his label be slapped on that.