New Orleans Saints players and at least one assistant coach maintained a bounty pool of up to $50,000 in the last three seasons to reward game-ending injuries inflicted on opposing players, including Brett Favre and Kurt Warner, the NFL said Friday. “Knockouts” were worth $1,500 and “cart-offs” $1,000, with payments doubled or tripled for the playoffs. The NFL said the pool amounts reached their height in 2009, the year the Saints won the Super Bowl. The league said 22 to 27 defensive players were involved in the program and that it was administered by defensive coordinator Gregg Williams, with the knowledge of coach Sean Payton. Williams apologized for his role: “It was a terrible mistake, and we knew it was wrong while we were doing it,” he said. No punishments have been handed out, but they could include suspension, fines and loss of draft picks. The NFL said the findings were corroborated by multiple, independent sources, during an investigation by the league's security department. Players contributed cash to the pool, at times large amounts, and in some cases the money pledged was directed against a specific person, the NFL said. “The payments here are particularly troubling because they involved not just payments for ‘performance,' but also for injuring opposing players,” Commissioner Roger Goodell said in a statement. “The bounty rule promotes two key elements of NFL football: Player safety and competitive integrity.” All payouts for specific performances in a game, including interceptions or causing fumbles, are against NFL rules. The NFL also warns teams against such practices before each season. “It is our responsibility to protect player safety and the integrity of our game, and this type of conduct will not be tolerated,” Goodell said. “We have made significant progress in changing the culture with respect to player safety and we are not going to relent. We have more work to do and we will do it.” Asked about potential criminal charges, NFL spokesman Greg Aiello said: “We believe that any violation of league rules should and will be handled by the commissioner.” The league absolved Saints owner Tom Benson of any blame, but said the investigation showed Payton and general manager Mickey Loomis knew about the improper “pay for performance” program. “Although head coach Sean Payton was not a direct participant in the funding or administration of the program, he was aware of the allegations, did not make any detailed inquiry or otherwise seek to learn the facts, and failed to stop the bounty program. He never instructed his assistant coaches or players that a bounty program was improper and could not continue,” the NFL said. When informed about it, the NFL said Benson directed Loomis, to “ensure that any bounty program be discontinued immediately.” However, the NFL's report said evidence showed Loomis didn't carry out Benson's directions and that in 2010, Loomis denied any knowledge of a bounty program. “There is no evidence that Mr. Loomis took any effective action to stop these practices,” the NFL said.