NFL Commissioner Roger Goodell wrote to team owners, “At times … we fall short of our goals.” (AP Photo/David Goldman)

The NFL will increase its penalties for players involved in future domestic violence cases, Commissioner Roger Goodell informed team owners in a letter Thursday.

Players who commit future acts of domestic violence will be subject to a six-game suspension for a first offense and a lifetime ban from the sport for a repeat offense, Goodell wrote in the letter. A repeat offender would be permitted to apply to the league for reinstatement after one year.

The toughened penalties came after the league and Goodell received widespread criticism for the two-game suspension given to Baltimore Ravens running back Ray Rice for his involvement in a domestic violence case earlier this year.

Goodell, without mentioning Rice by name, wrote in the letter that he’d erred in his decision.

“At times… and despite our best efforts, we fall short of our goals,” Goodell wrote. “We clearly did so in response to a recent incident of domestic violence. We allowed our standards to fall below where they should be and lost an important opportunity to emphasize our strong stance on a critical issue and the effective programs we have in place. My disciplinary decision led the public to question our sincerity, our commitment, and whether we understood the toll that domestic violence inflicts on so many families. I take responsibility both for the decision and for ensuring that our actions in the future properly reflect our values. I didn’t get it right. Simply put, we have to do better. And we will.”

The suspensions would be without pay and the policy applies to all NFL personnel, Goodell wrote.

Goodell wrote that consideration would be “given to mitigating factors” on a first offense, but a suspension of longer than six games also would be possible “when circumstances warrant.” A repeat offender who applies for reinstatement to the league after one year would be given “no presumption or assurance that the petition will be granted,” Goodell wrote.

In the letter, a copy of which was obtained by The Washington Post and other media organizations, Goodell wrote that he had reviewed all aspects of the league’s personal conduct policy with owners, the NFL Players Association and outside experts.

The NFL Players Association, after initially declining to comment through a spokesman, issued a written statement that said: “We were informed today of the NFL’s decision to increase penalties on domestic violence offenders under the Personal Conduct Policy for all NFL employees. As we do in all disciplinary matters, if we believe that players’ due process rights are infringed upon during the course of discipline, we will assert and defend our members’ rights.”

In recent weeks, people familiar with the thinking of players’ union officials had left open the possibility of the union challenging increased penalties for players for future domestic violence cases if the NFL implemented such changes unilaterally. Those people contended that any changes to the personal conduct policy must be collectively bargained with the union.

“The public response reinforced my belief that the NFL is held to a higher standard, and properly so,” Goodell wrote in his letter to the owners. “Much of the criticism stemmed from a fundamental recognition that the NFL is a leader, that we do stand for important values, and that we can project those values in ways that have a positive impact beyond professional football. We embrace this role and the responsibility that comes with it. We will listen openly, engage our critics constructively, and seek continuous improvement in everything we do.

“We will use this opportunity to create a positive outcome by promoting policies of respect for women both within and outside of the workplace. We will work with nationally recognized experts to ensure that the NFL has a model policy on domestic violence and sexual assault. We will invest time and resources in training, programs and services that will become part of our culture. And we will increase the sanctions imposed on NFL personnel who violate our policies.”

The NFL’s announcement drew praise from groups focused on preventing violence against women and others.

“Thank you, Roger Goodell and your staff, for acknowledging that now is the time for the NFL to demonstrate leadership on the issue of domestic violence prevention and education,” Esta Soler, the founder and president of Futures Without Violence, and Peter Harvey, a board member for the group and a former New Jersey attorney general, said in a joint written statement. “You have taken some good first steps to build a meaningful strategy that deals effectively with violence against women.”

Sen. Richard Blumenthal (D-Conn.) said in a written statement: “Today’s historic announcement puts the NFL at first down and goal to go. This very serious and significant step matches the severity and prevalence of domestic violence in our society and could make the NFL part of the solution, rather than the problem. I applaud Commissioner Goodell for taking positive steps to address the festering issue of domestic violence in the National Football League, but now the real work begins. The Commissioner and the League must match words with actions.”

Goodell wrote in his letter than the league will continue to work with domestic violence experts on the issue and will provide enhanced training for players, beginning when they are rookies first entering the league, and other personnel. Teams’ player engagement directors and human resource officers will undergo extensive training on domestic violence matters, Goodell wrote.

Rice was suspended without pay from the Ravens’ first two games of the upcoming 2014 season and was fined an additional game check based on last season’s salary. The NFL’s penalty costs him approximately $529,000. Many media members and other observers called the punishment insufficient and said it sent the wrong message about the NFL’s attitude toward domestic violence. Goodell previously defended the penalty, but people close to the situation said in recent weeks that increased penalties were under serious consideration and likely would be implemented before the season.

Rice was involved in an incident in February in which he allegedly struck his fiancée, Janay Palmer, in an elevator in an Atlantic City hotel. Video that become public showed Rice pulling Palmer, who was apparently unconscious, from the elevator. Rice pleaded not guilty to a third-degree aggravated assault charge and was accepted into a pretrial intervention program, avoiding trial. He and Palmer later married.