Wearing a white T-shirt and khaki shorts, the gunman approached three teenagers waiting at a Broadmoor bus stop from behind, then let loose a barrage of gunfire.

Police said in a report released Tuesday that a surveillance camera captured 27-year-old Samuel Ash committing Monday’s triple shooting at the corner of Washington Avenue and South Broad Street. The footage was provided by the same Cajun Seafood restaurant where the alleged shooter had just bought a shrimp platter.

Police said Ash acted methodically, firing the initial burst of shots and then standing over one 17-year-old victim as he lay on the ground and firing again.

As witnesses inside the seafood store screamed, Ash allegedly hopped into his SUV and took off down Broad toward Tulane Avenue.

NOPD Street Gang Unit officers, who happened to be in the area, gave chase. Ash’s flight ended in a car crash, his arrest and the recovery of a Glock .45-caliber handgun. Police said that spent casings from a weapon of the same caliber were found scattered around the crime scene.

The result for Ash was a $640,000 bail, set Tuesday morning in Magistrate Court, and three counts of attempted first-degree murder.

The victims of Monday’s shooting were left recuperating from serious injuries.

A 16-year-old boy had gunshot wounds to his liver, kidney and diaphragm. The 17-year-old took shots to his right arm and lower back. And a 14-year-old girl suffered a gunshot wound to her left leg.

One of the victims remained in critical condition at the hospital Tuesday, NOPD spokesman Tyler Gamble said .

Gamble said police were not prepared to confirm a motive in the shooting spree. But witnesses told WWL-TV on Monday that it may have been over a cigarette. One of the teens refused to give Ash a smoke, onlookers told the station.

Court records show that Ash was out on bond on a marijuana possession charge.

Reached by telephone Tuesday, Ash’s aunt, Tammy Simmons, said she did not believe the news reports of her nephew’s alleged shooting spree.

“He has never been involved in anything like that,” she said.