Detectives this week took DNA samples from the cheeks of ex-New Orleans Police Department Capt. Billy Ceravolo and the couple who was riding with former Saints defensive lineman Will Smith when he was fatally shot in the back last month, according to a source familiar with the investigation.

Ceravolo, as well as Richard and Rebecca Dooley Hernandez, gave their DNA voluntarily. Police are looking to see whether any of those buccal swab samples match unidentified genetic material found on the loaded but unfired gun that police found in Smith’s Mercedes SUV, the source said.

Following a volatile altercation after a traffic collision on Sophie Wright Place late on April 9, Smith lay dead in the driver’s seat of the Mercedes. He was shot eight times — seven in the back.

Cardell Hayes, 28, was indicted last week for Smith’s killing and the injuries suffered by his wife, Racquel Smith, from gunshots to each leg. His attorneys have described Hayes as “not legally guilty” and “not the aggressor,” suggesting a self-defense claim in the shooting.

Ceravolo and former Saints running back Pierre Thomas, close friends of the Smiths, had dined with them that night at Sake Cafe on Magazine Street, and both appeared at the scene of the crash and killing.

Hayes’ attorneys, John Fuller and Jay Daniels, have suggested that Ceravolo meddled with the crime scene, and at a preliminary hearing last week, a defense investigator testified that a witness told him she saw Ceravolo pluck a gun from the Mercedes.

Ceravolo’s attorney, Tanya Picou Faia, has denied that allegation, and on Friday she said she “actively requested” that detectives take a sample of Ceravolo’s DNA “to prove he has never been in (Smith’s) vehicle, ever.”

Detectives took the sample Thursday in Faia’s office, she said.

Ceravolo also found a blood stain on the yellow shirt he wore that night, and Faia said she alerted authorities early last week and turned it over for testing.

Faia said Ceravolo had driven to the Windsor Court hotel downtown after dining with the Smiths when he got phone call alerting him to the shooting. Ceravolo then high-tailed it to the scene.

“The caller told him, ‘Will is dead.’ He already knew in his mind Will was gone. He didn’t go there with any intention of looking at Will. He never went near the car,” Faia said. “He went straight to Racquel.”

Faia said Ceravolo suspects the blood on his shirt is Racquel Smith’s.

Ceravolo, now a reserve officer, has been curbed from duty pending a police review of his involvement at the scene, according to police.

The Hernandez couple also gave DNA samples this week, the source said. Their attorney, Martin Regan, described them Thursday as friends and neighbors of the Smiths with children who play sports together. Regan insisted they did nothing to threaten Hayes or Kevin O’Neal, the passenger that night in Hayes’ orange Hummer.

Regan declined to say whether Richard Hernandez was the man witnesses identified as agitated, shirtless and charging at Hayes and O’Neal following a three-car collision before the gunfire erupted.

“They were out simply to have dinner with the Smiths and had a few drinks and did not at any time expect the behavior by Mr. Hayes, nor can they justify it,” said Regan, who could not immediately be reached Friday for comment about the DNA samples.

Hayes last week pleaded not guilty to a four-count indictment accusing him of second-degree murder, attempted murder, aggravated assault and criminal damage to property.

He remains jailed on $1.75 million bond. A request by Hayes’ attorneys to reduce that bond will be heard before Criminal District Judge Camille Buras on June 3.

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