A Marine has pleaded not guilty to murder in the death of a Camp Pendleton comrade who prosecutors say was killed in a dispute over stolen drug money.

Pfc. Alvin Reed Lovely entered his plea during an arraignment Friday in Orange County Superior Court.

The body of Pfc. Stephen Serrano was found May 15 in a ditch in San Clemente.

Another Marine charged with murder in the case, Lance Cpl. Christian William Carney, is being held at Camp Pendleton where he faces unrelated drug dealing charges. Authorities say he will face the murder charge after disposition of his drug case.

In a statement issued by the Orange County District Attorney's Office, prosecutors allege that Serrano and an unidentified Marine broke into Carney's room at the base on May 9 and stole drug money.

Prosecutors say Carney was dealing ecstasy and cocaine on the base.

Four days later, another unidentified Marine told Carney that he had witnessed two men, including a mutual friend, breaking into Carney's room, prosecutors said. Later that day, Carney and Lovely allegedly met Serrano's alleged accomplice and drove him from the base to a secluded location in San Clemente. They put a gun to the Marine's head and threatened to shoot him if he didn't identify his alleged accomplice in the burglary.

The man identified Serrano, prosecutors said.

Carney and Lovely returned to the base and asked Serrano to meet them, according to prosecutors. The men drove Serrano to San Clemente, shot him once in the head and three times in the back, prosecutors said.

Carney, 21, and Lovely, 20, are charged with one count each of murder and making a criminal threat. They also face a sentencing enhancement for the personal discharge of a firearm. Carney also faces a charge of attempting to dissuade a witness.

All three Marines were assigned to the 1st Marine Division.