Derrick Miller walked out of the Fort Leavenworth military detention barracks last week a free man for the first time in nearly a decade. Nine years ago as a Maryland National Guardsman on his third tour of duty, Miller shot and killed an unarmed Afghan during a battlefield interrogation. Miller said he shot the man in self-defense, after a scuffle over his weapon; prosecutors said Miller always planned to kill the man. He was charged with premeditated murder and sentenced to life in prison. In the years since, his case was taken up by an organization called United American Patriots, which advocates for service members accused of crimes in war zones. Its director, David Gurfein, is a Marine veteran who served in Afghanistan and both Gulf Wars. In the one year since he took over the organization, it's raised and spent hundreds of thousands of dollars on legal defense and public outreach, including to members of Congress. Subscribe to VICE News here: http://bit.ly/Subscribe-to-VICE-News Check out VICE News for more: http://vicenews.com/ Follow VICE News here: Facebook: https://www.facebook.com/vicenews Twitter: https://twitter.com/vicenews Tumblr: http://vicenews.tumblr.com/ Instagram: http://instagram.com/vicenews More videos from the VICE network: https://www.fb.com/vicevideo