 -- The NFL Players Association announced tonight it is appealing the suspension of former Baltimore Ravens running back Ray Rice.

"The NFLPA appeal is based on supporting facts that reveal a lack of a fair and impartial process, including the role of the office of the Commissioner of the NFL," the union said in a statement tonight.

"We have asked that a neutral and jointly selected arbitrator hear this case as the Commissioner and his staff will be essential witnesses in the proceeding and thus cannot serve as impartial arbitrators," the NFLPA said.

The NFL suspended Rice indefinitely and the Ravens terminated his contract last week after video surfaced of the running back punching his then-fiancee unconscious in an Atlantic City casino elevator on Feb. 15.

The newly-emerged video shows Janay Palmer, now Rice's wife, being hit in the face in the elevator. Palmer then lunges at the running back before he delivers a blow that knocks her out. When the elevator doors open, Rice drags Palmer's body outside, leaving her face down on the floor, her legs still inside the elevator.

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Both Rice and Palmer were arrested after the incident. Charges against Palmer were quickly dropped. Rice, who was indicted by a grand jury, entered a pretrial diversionary program, avoiding jail time. He has apologized for the Feb. 15 incident.

After outrage from Rice's suspension, the NFL announced last month that players accused of domestic violence would face tougher punishments. Players get six games of suspension for a first offense, and at least a year for a second offense, according to the new policy.