After video surfaced on the TMZ Sports website showing the NFL player dragging an apparently unconscious woman out of a Revel elevator, the case was referred to the Prosecutor's Office for review.
The announcement from Prosecutor Jim McClain characterized the alleged assault as occurring "in an Atlantic City casino/hotel elevator." Some witnesses were quoted as saying they saw the pair in a Revel nightclub early Feb. 15.
Rice and Palmer live in Reisterstown, Md. Their attorneys have said neither wanted to pursue charges. The simple-assault charge against Palmer was administratively dismissed.
Rice's attorney, Michael Diamondstein of Philadelphia, said Thursday that Rice "vehemently denies" that he committed an aggravated assault.
"We do not believe as a matter of law that the charges can be substantiated," Diamondstein said. "Neither Mr. Rice nor Ms. Palmer wish to go forward in this matter."
He said Revel had refused to turn over the video to him, and would not comment any further on the incident. He said Rice and Palmer were "still together, in counseling and happy."
Ravens owner Steve Bisciotti said this week at the league owners' meetings that Rice's arrest was "embarrassing and disappointing" but that he would still support the running back. The NFL is also monitoring the case.
The Ravens said on their website Thursday, "This is part of the due process for Ray. We know there is more to Ray Rice than this one incident."
The indictment is for one count of aggravated assault "for attempting to cause significant bodily injury, and/or purposely or knowingly causing such injury, and/or recklessly causing such injury under extreme indifference to the value of human life."