By Marty Graham CAMP PENDLETON, Calif., Oct 16 (Reuters) - A defense lawyer said on Monday that he would challenge the testimony of a Navy medic who said anger motivated Sgt. Lawrence Hutchins III to lead his unit in randomly killing an Iraqi grandfather. Hutchins, the alleged ringleader in the killing, appeared briefly in military court on Monday as prosecutors and defense attorneys submitted evidence to the U.S. Marine Corps investigating officer deciding whether to take the matter to trial. His lawyer, J. Richardson Brannon, spoke to reporters 10 days after Navy medic Melson Bacos made a plea deal under which he agreed to testify against others accused in the case. Although the military judge recommended a 10-year sentence, the plea deal set a one-year maximum penalty for Bacos. "It is suspect to me," Brannon said. "When you can walk away from a murder case, walk away and be a free man ... that's a pretty large inducement." According to Bacos, Hutchins led the unit in planning to kidnap and kill a terror suspect in the middle of the night in the Iraqi town of Hamdania. But when the unit could not find the suspect, they randomly executed Hashim Ibrahim Awad, 52, a father of 11 and grandfather of four who lived next door. Bacos said Hutchins fired bullets into the man's head. Investigating officer Col. Paul Pugliese made no ruling on Monday but is expected to bind Hutchins over for court martial in Awad's death. Seven Marines and one Navy corpsman have been charged with murder, kidnapping, giving false statements and conspiracy in the April killing. If convicted, the Marines face life in prison. The Marine Corps is grappling with allegations of troop misconduct in Iraq, including this incident and the alleged massacre in November of two dozen civilians in the town of Haditha by Marines from another unit. Monday's proceedings, held at Camp Pendleton north of San Diego, were brief and perfunctory without testimony. The hearing officer accepted 40 exhibits from prosecutors and 11 from defense attorneys. The exhibits mostly consist of written statements of Naval Criminal Investigative Service investigators, the Marines involved and Iraqi civilians. The Article 32 hearing, a preliminary review of evidence, was the last in the Hamdania cases.