Who would have thought Dom DeLuise would be the man to turn Washington's "Sting" operation into a movie?

Three years ago, when police departments across the country started going into the fencing business, a number of producers talked of making the concept the basis for a movie. In the end, none did. Now we know why.

The plan had simply worked too well. Not only were theives peddling their wares to police officers pretending to be underworld figures, but, once bamboozled, they were so anxious to continue the relationship that the police were not even obliged to put on a good act.

Here in Washington, for instance, the "Sting" undercover agents gave themselves names like "Angelo Lasagna" and "Tony Bonnano," served outrageously spicy meatballs to their customers, and, at their climactic party-cum-round-up, had everyone kneel and kiss the ring of a "Don" wearing a suit from J.C. Penney's.

There were a few suspenseful questions, of course. Would the videotape equipment function properly? Would the police officers be able to keep a straight face? But movies, even ones involving Dom DeLuise, need more suspense than that.

They also need more comedy than DeLuise has been able to provide either as the director or star of "Hot Stuff," which limps into six suburban theaters today.

"Hot Stuff's" idea of a laugh is Detective Ossie Davis, in a tight spot, asking, "Where's a cop? You can never find a cop when you need one!" Or an aristocratic Englishwoman trying to hard-sell DeLuise into buying a load of "the best s-- - you're ever going to smoke" -- and DeLuise getting outrageously high when he agrees to test-smoke a sample. Or DeLuise, period, eating, suffering, excreting -- doing anything in short, that comes naturally.

The movie opens with a long and furious car (plus-boat-plus-foot) chase that is as laugh-free as anything since Stanley Kramer's "It's a Mad Mad Mad World," But it may no longer be possible, in fairness, for a car chase to be funny, so DeLuise can be exonerated on this count.

Set in Miami and evidently designed for the grits circuit, "Hot Stuff" has found an appropriate romantic lead in country singer Jerry Reed, Burt Reynolds' sidekick from "W.W. and the Dixie Dancekings," "Gator" and "Smokey and the Bandit." At first glance, Suzanne Pleshette comes across as a far stranger choice for this particular milieu -- and at second and third glance, too. But she is good to glance at, and seems to have taken the assignment so casually that she doesn't make the rest of the cast look as bad as she might.

The writers of "Hot Stuff," -- Michael Kane and old police hand Donald Westlake -- have labored hard and long to give their police heroes the look of underdogs. They have portrayed the whole operation as an unauthorized mission the chief must disavow if it misfires. They have introduced a trio of real mafiosi who warn our undercover heroes to get out of town or else. And at the final roundup (Otherwise modeled closely on Washington's), they have left our detectives alone and dangerously outnumbered by the criminals they mean to arrest.

But "Hot Stuff's" zany assortment of thieves -- including a snooty yachtsman and his wife, a midget, a weight-lifter with a set of hot barbells, and a poor little boy trying to pawn his dog so he can buy something to eat -- tend to shift the odds right back again. With robbers this dumb, who needs cops?