(Reuters) - An independent probe has found no evidence that anyone at the NFL possessed or saw the surveillance video of running back Ray Rice striking his then-fiancee last year but said the league failed to properly investigate the case.
The investigation, led by former FBI director Robert Mueller, concluded the league "should have done more with the information it had."
The report faults the NFL for yielding to law enforcement in Rice's case and not pushing for more evidence. But it does not place blame on embattled league commissioner Roger Goodell, who has absorbed the brunt of public criticism.
"We found no evidence that anyone at the NFL had or saw the in-elevator video before it was publicly shown," said a release summarizing the findings of the fourth-month probe.
Mueller's report recommended that the NFL establish a special domestic violence and sexual assault investigative team and adopt guidelines for investigations.
The Rice incident, along with a spate of domestic abuse cases among players including Minnesota Vikings star Adrian Peterson, brought down a firestorm of public criticism on the most popular U.S. sports league as it sought to woo female fans, a key growth area.
"We have all learned a great deal in the past months and expect to be judged by how we lead going forward on issues of domestic violence and sexual assault," Goodell said in a statement.
Goodell initially suspended Rice for two games for punching Janay Palmer, who fell unconscious in an elevator during an argument at an Atlantic City, New Jersey, casino in February last year.
Goodell reversed course and suspended Rice indefinitely in September when surveillance video was released by website TMZ showing the punch. The league had said it never saw the video and would have acted differently if it did.
Rice, one of the league's top running backs, was also released from his $35 million contract with the Baltimore Ravens.
New York Giants President John Mara and Pittsburgh Steelers President Art Rooney II, who both oversaw the Mueller investigation, conceded in a statement the issue "has tarnished the reputation of the NFL" but backed Goodell as commissioner.
Goodell has admitted he "didn't get it right" in such cases. Last year, many domestic abuse advocates called for his resignation while league sponsors sought to distance themselves from the NFL as public criticism intensified.
Mueller's investigation also found no evidence that a league employee had acknowledged receipt of the video as had been reported by the Associated Press, which had cited an unnamed source.
The news agency's executive editor Kathleen Carroll said in a statement the company declined to provide Mueller's investigators with information and it stood by its reporting.
After the wave of criticism that followed the incident, the NFL said it was toughening its stance on domestic violence and personal conduct among players and employees.
Now, players are subject to a mandatory six-game ban for a first domestic violence offense and indefinite suspension for a second violation.
Goodell also will no longer make initial rulings in misconduct cases but will remain in charge of appeals. The NFL has brought on board several female executives to help the league address image problems.
The independence of the report has come under fire since Mueller is a partner at WilmerHale, the law firm that represented the NFL during negotiations with DirecTV over the NFL's $4 billion "Sunday Ticket" package.
Three other former WilmerHale lawyers also now work for the NFL, including Richard Cass, the president of the Ravens.
Rice, who is now married to Palmer, won an appeal of his suspension in November and is a free agent.
Additional reporting by Eric Kelsey in Los Angeles; Editing by Jeffrey Benkoe and Alan Crosby