A 24-year-old man was charged yesterday with first-degree murder in a slaying that was captured in vivid detail by security cameras at a Southeast Washington gas station, authorities said.

Antonio D. Reed, 24, was arrested Wednesday afternoon by police and U.S. marshals. He later was charged with taking part in the killing of Dewayne James, 20, on May 2. Police said they are trying to identify a second assailant, who allegedly pulled the trigger.

James was buying a soda at the Lowest Price Food Mart at Benning Road and East Capitol Street SE about 11:30 p.m. when he was approached by Reed, who was wearing a blue North Face baseball cap, police said. The video shows the man wearing a cap arguing with James and getting into a fight. The assailant then appears to hit James with a pistol. The pair struggle, throw punches and wrestle on the ground.

About 30 seconds into the fight, a man dressed in camouflage can be seen on the video quickly approaching the two men struggling on the ground. This man leans over, puts a silver pistol to James's head and apparently fires, the video shows.

The video then shows the two assailants running away. James, of the 4700 block of B Street SE, was struck in the head by two bullets and died at the scene, police said.

Police said that they found the North Face hat at the shooting site and that technicians recovered potential DNA evidence from it. The evidence from the hat is being processed, they said.

Though they had the hat and videotape, police grew frustrated over their lack of witnesses and on May 18 released the security footage to the media. Television stations aired it repeatedly.

Police said a witness eventually came forward and told detectives that Reed had admitted to playing a role in the killing.

Reed, of the 100 block of 42nd Street NE, was arrested on a warrant charging him with a killing in Prince George's County. Police provided no details about that slaying yesterday.

A D.C. Superior Court judge ordered Reed held without bond in the killing of James, pending a preliminary hearing set for Aug. 4.

Charging papers quote Reed as telling detectives that he was having problems with James and saw him walking toward the gas station May 2. Reed told police that he then got a pistol and approached James, the charging papers state.

The two argued, and after an "intense struggle," the man in camouflage approached and shot James, police wrote. Police said they have been unable to identify the gunman, and they urged anyone with information to call detectives at 202-727-9099.

As one assailant struggles with Dewayne James at a gas station in Southeast Washington, another, in camouflage, apparently shoots him with a silver handgun. Police said they have not identified the man in camouflage.Police say this hat from the crime scene yielded DNA evidence.