Marine Arrested in Slaying of Tustin Man, 18 : Homicide: The victim died of a bullet wound to the chest suffered outside a convenience store after a short argument with a sergeant from the helicopter base.

Police on Thursday arrested a U.S. Marine mechanic on suspicion of murder in the shooting of a young Tustin man outside a convenience store.

Marine Sgt. Timothy C. Carter, 27, a 10-year veteran stationed at the Tustin helicopter base, was being held in Orange County Jail on $250,000 bail, a Sheriff’s Department spokesman said.

Carter is accused of killing David Lee Walker, 18, who lived near the Circle K Market where he was shot at 11:45 p.m. Wednesday, Police Lt. Houston Williams said. Walker died at the scene from a single bullet wound to the chest.

Williams said the shooting was sparked by a short argument between Carter and Walker. Carter allegedly lost his temper during a “stare-down,” Williams said.

“It was basically a ‘What-are-you-looking-at’ type of situation,” Williams said.

The police investigation was complicated at first by the fact that Walker carried no identification, and a car with a military base pass attached to the bumper was left near Walker’s body, Williams said. Police at first thought the car belonged to Walker and that he was a Marine.

Walker was identified Thursday afternoon through the Sheriff Department’s statewide computer identification system because he had been convicted of assault and battery as a juvenile and was on probation, Williams said.

The series of events began almost almost three hours before the shooting, when Carter and his unidentified girlfriend, who also lived near the Circle K, had an argument outside the store. She reportedly struck him and he called police, Williams said.

She walked back to her apartment, leaving Carter alone. But when officers arrived, he declined to file a police report.

Hours later, Carter was again outside the store, at McFadden Street and Pasadena Avenue, waiting for a fellow Marine, a corporal, to make a phone call, Williams said.

As Walker passed Carter, a few harsh words were exchanged, and Carter allegedly pulled out a handgun, shooting Walker in the chest. The gun was not a military weapon, a Marine spokeswoman said.

While Walker staggered about 30 feet to a grassy area and fell, his friend fled on foot, as did Carter and the corporal, who left his car at the scene, Williams said.

Store manager Harry Singh said the two night clerks manning the cash register heard a loud pop but thought that it was a car backfiring.

“They didn’t think about it,” Singh said. But a few seconds later, a woman came running into the store, screaming to the clerks to call the police.

Carter apparently ran to another Marine’s apartment, Williams said. He and that friend then drove off in the friend’s car. At 1 a.m., they awere stopped by a Newport Beach patrolman because the car had a broken windshield. Carter’s handgun was found on him, and he was taken into custody for possession of a concealed weapon.

Meanwhile, Tustin police contacted military police to find out who owned the car at the Circle K.

“We assumed (Walker) was the corporal,” Williams said.

It was not until Thursday afternoon that it occurred to Tustin, Newport Beach and military police that the corporal was accounted for and Carter was the prime suspect in the murder.

“We started putting two and two together,” Williams said.

Carter was then booked on suspicion of murder and transferred to County Jail. He faces an arraignment on murder charges today in Central Municipal Court.

Marine Capt. Betsy Sweatt said Carter, originally from Roanoke, Va., has a good record in the military, earning three good conduct medals, a meritorious unit commendation and a sea service ribbon since he joined the Marines on Oct. 14, 1980.

Carter will not be provided a military attorney, since he is accused by civilian authorities, Sweatt said. He was not on duty at the time of the shooting and not in uniform. The gun was legally registered to him.

Sweatt said the military will not decide whether to take any action against Carter until after his case is disposed of in the civilian courts. But she added, the Marine Corps has the option of prosecuting him, even if the civilian court system decides not to file charges.

In the meantime, Carter is considered “technically away without authority,” Sweatt said. She did not elaborate on the implications of that status.