(CNN) -- A federal appeals court on Tuesday rejected a former San Francisco Bay Area Rapid Transit officer's claim of immunity in the shooting death of Oscar Grant, clearing the way for the 22-year-old's father to sue over the controversial killing on a train platform.
Johannes Mehserle was convicted of fatally shooting Grant in the back on New Year's Day in 2009 as he lay on a platform at the Fruitvale BART Station in Oakland, a case that is recounted in the award-winning movie "Fruitvale Station."
The 9th U.S. Circuit Court of Appeals denied Mehserle's claim that "the facts overwhelmingly show that he was acting consistently within the legitimate law enforcement objective of arresting Grant," upholding a lower court ruling that found there was a "genuine issue" as to whether the former officer's actions were required for a legitimate law enforcement purpose.
Mehserle testified at his 2010 trial that he intended to draw and fire his Taser rather than his gun. He was sentenced to two years in prison after his involuntary manslaughter conviction but was released after serving 11 months because of a California law that allowed him to reduce his sentence to nearly a year.
The shooting gained national attention in large part because it was captured on an onlooker's cell phone video camera. The video showed Mehserle pulling his gun and shooting Grant in the back as another officer appeared to be kneeling down over the unarmed man.
The video was widely circulated on the Internet and on news broadcasts, and it spurred months of protests in and around Oakland.
Violent protests erupted after Mehserle's sentence was handed down, with at least 150 people arrested by the police.
The case has continued to draw interest and questions, with first-time director Ryan Coogler tackling the story in the independent film "Fruitvale Station" that was released this year. The film chronicles the last day of Grant's life.
The movie made its premiere at the 2013 Sundance Film Festival, where it took home the U.S. Grand Jury Prize and an Audience Award. It went on to win the award for Best First Film at the 66th Cannes Film Festival.
Coogler wrote the film, which stars Michael B. Jordan, Octavia Spencer, Kevin Durand and Chad Michael Murray.