OCEANSIDE, Calif. — A military trial begins Tuesday for a Marine sergeant charged with unpremeditated murder and dereliction of duty in the death of a detainee during the 2004 Battle of Fallujah, Marine officials said.Navy Capt. Keith Allred, a military judge, will preside over the general court-martial at Camp Pendleton for Sgt. Jermaine A. Nelson, who faces one count of unpremeditated murder and two counts of dereliction of duty.Military prosecutors contend that Nelson shot and killed a man allegedly detained while Nelson and members of his squad with 3rd Battalion, 1st Marines, were inside a house Nov. 9, 2004, the opening day of the intense urban battle. Authorities say he violated international law and military rules of engagement for failing to follow standard procedures for handling detainees.Nelson has denied the allegations. Defense attorneys have contended that the shooting was justified because the man was a combatant.Lt. Gen. Samuel Helland, most recently the commander of Marine Corps Forces-Central Command and I Marine Expeditionary Force at Camp Pendleton, referred the charges against Nelson.One of Nelson’s former squad members, Sgt. Ryan Weemer, was acquitted by a military jury of similar charges during an April court-martial.Their squad leader at the time, former Sgt. Jose Nazario Jr., was charged in federal court last year but was acquitted by a civilian jury following a trial in which Nelson, Weemer and Nazario refused to testify. Nelson and Weemer were jailed for contempt of court, but the judge later released them.The military prosecutions and federal charges stemmed from a Naval Criminal Investigative Service investigation prompted by comments Weemer made during a pre-polygraph exam with the U.S. Secret Service.More onlineMarine jailed indefinitely, refusing to testifyWeemer: ‘Tormented’ by FallujahAccused in killing, former Marine speaksFeds want sgt. detained for contempt — again