A suspect is getting grilled by three cops, played by movie stars.

At one point, the biggest star of them all, Alec Baldwin, blurts out “Need I remind you you’re under OATH?”

No, the director didn’t shout “Cut!” No, the writer didn’t correct this, because he almost certainly wrote that blunder into his seriously under-researched screenplay.

And no, the hapless bit player being grilled didn’t have the temerity to say, “Excuse me, this is an interrogation, not a COURT of law. What ‘oath?'”

Terrence Howard, Esai Morales, Nicky Whelan and Baldwin star in the Little Rock-set “Crescent City,” a sordid, sloppy and over-sexed thriller that’s an embarrassment for all concerned.

Screenwriter Rich Ronat — he co-wrote the Nic Cage bomb “Grand Isle” — apparently watched an episode or two of “Blue Bloods” as his research. And dozed off between the commercial breaks. But while he can be blamed for some of the head-scratchingly stupid blunders and eye-rolling “twists” that constantly trip up this script, there’s little he can do about a filmmaker who casts the dullest actor available to play a preacher, or the quirk of injecting an attractive Aussie (Nicky Whelan of “The Flood, “Man eater” and “The Nana Project”) into the narrative.

Whelan plays a thick-accented blonde bombshell of a cop who “transferred from Tulsa.” Um, okay. But Tulsa’s in another jurisdiction, another city and another STATE. How’d she “transfer?”

Stupid stumbles like that pile up like headless corpses in this serial killer thriller where the connection might be a church Sex Addicts Anonymous group, or somebody with a beef with one or more of the detectives investigating the case, or someone who works in a manikin factory.

Because that’s one of the trademarks of this trail of entrails killer — leaving a fake head at the scene of the crime.

Howard plays a family man, a churchgoer and a cop so haunted by earlier cases he’s having blackouts. Morales plays an impulsive, unfiltered, hard-drinking train wreck of a partner who lets his misogyny and other personal issues slip out mid-interrogation, mid-bar pickup and elsewhere.

And Baldwin’s the captain who’s got city hall “up my” you-know-what about this case and its rising body count.

We see one killing being committed, early on, but that doesn’t appear to be by an actual suspect, not going by the finale.

The murderer could be one of the people ID’d as a person of interest, a psychotically jealous spouse or one of the cops, each of whom has “secrets” that could implicate them in some way or other.

My money’s on Vlad, the coroner, who greets a widow standing over a sheet-covered slab with “Here’s the body!”

This RJ Collins film — he did “Don’t Suck,” and ignored his own advice — is notable for the attempts at kink and generally degrading sex scenes. I was a little shocked we didn’t visit a Little Rock strip club, as hard as this picture leans into “sordid” and producers usually insist on such scenes, just so they have an excuse to visit the set.

But no.

All three of the leading men have checkered personal histories and stains on their resumes, and “Crescent City” won’t be the film that chases away thoughts of their on-set accidents and off-set public moral (and legal) failings. But it is humbling to one and all, if that’s any consolation to those with “issues” with them.

Rating: R, graphic violence, explicit sex, profanity

Cast: Terrence Howard, Nicky Whelan, Esai Morales and Alec Baldwin

Credits: Directed by RJ Collins, scripted by Rich Ronat. A Lionsgate release on Tubi.

Running time: 1:43