A Marine lance corporal who said he had an aversion to killing and participating in war must be released from the military as a conscientious objector, a federal judge ruled.

The Marine Corps Reserves must discharge Robert Zabala, 23, by mid-April, under the ruling.

Zabala said he was troubled during boot camp in 2003 when a fellow recruit committed suicide and a superior used profanities to belittle the recruit. Zabala said he was "abhorred by the blood lust (the superior) seemed to possess," according to a 2006 court petition for conscientious-objector status.

Another boot camp instructor showed recruits a "motivational clip" showing Iraqi corpses, explosions, gun fights and rockets set to a heavy metal song that included the lyrics, "Let the bodies hit the floor," the petition said. Zabala said he cried, while other recruits nodded their heads in time with the beat.

"The sanctity of life that formed the moral center of petitioner's life was being challenged," his attorney, Stephen Collier, wrote in a court filing.

U.S. District Judge James Ware, who served 13 years in the Army Reserves, said he was convinced of Zabala's sincerity about his struggles to "reconcile the demands of duty with the demands of conscience."

Zabala, a student at the University of California, Santa Cruz, who followed some Buddhist-related traditions, was previously denied conscientious-objector status after applying in 2004, court records show.