U.S. soldier accused of Iraq murder contests sanity ruling TACOMA, Washington (Reuters) - Lawyers for a U.S. soldier charged with killing five fellow servicemen in 2009 at a military counseling center in Iraq asked an Army judge on Tuesday to reject a finding that the defendant is mentally fit to stand trial at a court-martial next month. Sergeant John Russell, who could face the death penalty if convicted, is accused of going on a shooting frenzy at Camp Liberty, near Baghdad airport, in an attack that the military said at the time could have been triggered by combat stress. Russell, who was attached to the 54th Engineer Battalion based in Bamberg, Germany, faces five charges of premeditated murder, one charge of aggravated assault and one charge of attempted murder in connection with the shootings. The state of Russell's mind, which has been the focus of legal proceedings over the past year, surfaced again in a pre-trial hearing at Joint Base Lewis-McChord near Tacoma. Defense lawyers asked the presiding judge, Colonel David Conn, to overturn the 2011 decision of a three-member "sanity board" that declared Russell competent to stand trial, or to at least reopen the board's review. Conn did not immediately rule on the request. A previous sanity board review, conducted in July 2009, found Russell unfit for trial, concluding that he suffered from "major depressive disorder," psychosis and post-traumatic stress disorder (PTSD). Russell subsequently underwent 20 months of treatment at a federal detention hospital in North Carolina before the second review found him competent. Defense lawyers on Tuesday sought to raise doubts about the credibility of one of the doctors who served on both reviews. The Army doctor, Colonel Ricky Malone, acknowledged in testimony by telephone that he sometimes drank to excess and had hangovers but insisted that alcohol had not affected his judgment during his evaluation of Russell. Questions of PTSD and psychosis have emerged in earlier hearings, most notably in testimony presented in November 2012 by Dr. Robert Sadoff, a University of Pennsylvania forensic psychiatrist who has examined Russell. Sadoff said he concluded that Russell was suffering from both PTSD and psychosis at the time of the shootings, as well as from a "dissociative disorder," or a lack of memory, about the incident. In a written submission, Sadoff also harshly criticized a psychologist and a psychiatrist on the staff at Camp Victory for what he called "inexcusable treatment" of Russell days before the shooting. Sadoff suggested then that Russell was "provoked to violence by the ineptitude and lack of compassion" by personnel assigned to treat him while he was in "an acute state of depression, with suicidal intent." Two of the five people killed were medical staff officers at the counseling center for troops experiencing combat stress. Evidence of PTSD or other some other mental illness could be used by defense lawyers in trying to convince jurors that the accused was unable to appreciate the nature and consequences of his actions - the definition of insanity under military law. Even if Russell were found guilty of murder, the defense could argue that he suffered from "diminished mental capacity," raising doubts about premeditation, which prosecutors must prove for him to be sentenced to death. The jury panel must be unanimous in approving capital punishment in the sentencing phase of a court-martial. The Russell case comes at a sensitive time for the Lewis-McChord base, one of the Army's largest. It is also the home base of Robert Bales, who is accused of killing 16 Afghan villagers last March and is scheduled to face a court martial in September. As in Russell's case, lawyers have suggested post-traumatic stress disorder may have been a factor in Bales's conduct. Earlier on Tuesday, an Army prosecution witness, staff sergeant Enos Richard, identified an M-16 rifle used in the Camp Liberty shootings as his and said Russell had taken it from him on the day of the shooting. Richard had been assigned to drive Russell to the stress center that day. A spokesman for U.S. forces in Iraq said in 2009 that a commander had earlier determined that Russell's own weapon should be taken from him. Conn asked Russell, who wore a green military uniform and glasses, whether he wanted military defense attorney Captain Ben Hillner, who has capital punishment legal expertise, to remain on his team of three lawyers. "I would like him to stay aboard, your honor," Russell said, softly. Writing by Eric M. Johnson; Editing by Kevin Liffey