CONEY ISLAND — He didn't bring a search warrant for his weekend exploits, but actor Vincent D'Onofrio, who plays a TV detective, tore up the beach in Brooklyn anyway.

With no cameras rolling, he put on quite a show in his civilian clothes — or bathing suit — and with his family, the "Law and Order: Criminal Intent" star won first-prize in Coney Island's Sand Sculpture contest.

It was a perfect beach day, and sand castles abounded, but the serious sculptors arrived at noon to begin shaping their giant mounds of sand into something a bit greater.

By 2:45 p.m., as the judges made their rounds, the stretch of beach between West 10th and West 12th streets along the boardwalk was decorated with larger-than-life sea turtles, mermaids and palatial kingdom estates.

Feet protrude from a first prize winning sculpture on July 21, 2012 in the Coney Island Sand Sculpting contest. View Full Caption DNAinfo/Alissa Ambrose

Curious beachgoers watched from Riegelmann Boardwalk or strolled between the artists at work. Some looked fearful of taking an errant step into the delicate works-in-progress.

Judges handed out awards in five categories: child alone, adult alone, group of adults, group of children and mixed groups.

Hector Patino, a New Jersey resident, won first place for the adult alone category, for a domestic violence awareness sculpture, featuring a woman covering her face in dispair.

The first prize for an adult group went to Frank Russo and some friends, who built a cartoony Harry Potter castle, with three leaning turrets.

Trinise, 9, and Amara Owens, 8, won first place in the children's group work category, for a giant tentacled 'Scary Octopus' entry, while Majatt Ajarar won first-place for her smiling sea turtle in the child alone category.

D'Onofrio and his eight-member family took home the first prize in the 'mixed' category, for an elaborate treasure chest that was guarded by sand skeletons, and decorated with gold coins.

"We love pirates!" said a Carin van der Donk, a former model and D'Onofrio's wife, as they sculpted.