The measures, announced in a letter from NFL commissioner Roger Goodell to all team owners, a copy of which was obtained by ESPN, apply to all NFL personnel.
A six-game suspension would be without pay and the length of the penalty could increase in these cases: an employee was involved in a prior incident before joining the NFL; violence involving a weapon; choking, repeated striking, or when the act is committed against a pregnant woman; or in the presence of a child. A second-time offender may petition for reinstatement after one year but there is no assurance the petition would be granted, the letter said.
A league source told ESPN's Andrew Brandt that discipline would be triggered by adjudication of a player's case, such as a conviction or plea agreement. The policy is not retroactive, meaning all personnel have a clean slate, a league source told ESPN's Mark Dominik. If a player commits a crime while in college or high school and then has a first offense while in the NFL, the player could be subject to a suspension harsher than six games.
The measures come partly in response to intense criticism Goodell received for his handling of discipline for Baltimore Ravens running back Ray Rice, who received a two-game suspension in July for assaulting his then-fiancee in February. Widely viewed as a soft punishment, Goodell left many with the impression that the NFL did not understand domestic violence or take it seriously as a crime.
Goodell acknowledged as much in the letter.
"At times, however, 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. ... 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."
To be counted as an "offense," a player would not necessarily have to be convicted in a court of law, but each incident will be judged on its own merits. The updated personal conduct policy had the approval of all 32 owners, Dominik's source said.
"Our personal conduct policy has long made clear that domestic violence and sexual assault are unacceptable. We clearly must do a better job of addressing these incidents in the NFL. And we will," the commissioner wrote.
Goodell was affected more by people closer to him, including some owners, than by public reaction, the source told Brandt.
The source told Brandt that Goodell had discussions with NFL Players Association executive director DeMaurice Smith and that lawyers for the league and union also talked, although it was unclear if an agreement was reached between the two sides.
The increased penalties for domestic violence did not have to be collectively bargained because they fall under the personal conduct policy.
The NFLPA reserved judgment in a statement released after the NFL's announcement.
"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," the union said.
The Ravens had no immediate comment on the new policy after it was announced Thursday.
They did, however, later announce a three-year partnership with House of Ruth, one of the nation's leading centers for helping victims of domestic abuse. It will include a $600,000 donation from the team, training for the players and staff and promotional work on behalf of the centers for abused women and children.
Rice, meanwhile, was not made available after the team's 22-13 preseason win against the New Orleans Saints on Thursday night, but coach John Harbaugh did address the topic.
"I haven't seen any of the comments or anything like that, but we respect the decisions that the commissioner has made in the past," he said. "We said we would respect his decisions throughout this whole thing and we will respect his decisions going forward in the future."
The league also announced a number of outreach measures. It will bulk up the domestic violence portion of the rookie symposium, identify at-risk personnel and offer preventative counseling, and also offer families a phone number as an emergency resource.
The NFL will also take that message on the road.
"We will expand the educational components in our college, high school and youth football programs that address domestic violence and sexual assault," Goodell wrote to owners.
The NFL instructs owners to distribute a memo to all personnel that details these new expectations and begins: "Domestic violence and sexual assault are wrong. They are illegal. They are never acceptable and have no place in the NFL under any circumstances."
In February, Rice was arrested on a charge of aggravated assault after knocking out his then-fiancee in an elevator in Atlantic City, New Jersey. Surveillance video showed Rice dragging Janay Palmer, who appeared unconscious, out of the elevator. Unreleased video showed Rice striking Palmer in the elevator.
In July, Goodell announced that Rice would be suspended for the first two games of the regular season. There was deep and sustained criticism from fans and groups who work with victims of domestic violence in response. The number of games was less than the suspensions given for most other infractions, such as substance abuse, steroid use or DUI offenses. The penalty for those items is determined by the collective bargaining agreement hammered out with the players' union in 2011.
Domestic violence infractions, however, fall under the personal conduct policy, which meant that Goodell alone was able to determine the severity of any fine or suspension. The fact the Ravens held a news conference with Rice in May and had Palmer sitting next to Rice on the dais also seemed to imply she shared responsibility -- whether or not that was the intention.
The fact Goodell reportedly allowed Rice's wife into the hearing to plead for leniency in front of her husband's employers struck many as inappropriate.
"Having done this work for many years, often a victim will say she doesn't want the abuser punished," said Judy Kluger, a former New York City judge and current executive director of Sanctuary for Families, after the decision was announced. "That shouldn't deter what an independent organization decides to do."
Information from ESPN.com Ravens reporter Jamison Hensley and ESPN.com Saints reporter Mike Triplett was used in this report.
NFL Implements Domestic Violence Penalties
espnW columnist Jane McManus discusses the NFL's sweeping domestic violence initiative that calls for a six-game suspension for a first offense and a lifetime ban from the league for a second offense.
Goodell Acknowledges Error In Rice Ruling
NFL Insiders Adam Caplan and Mark Dominik discuss commissioner Roger Goodell's acknowledgement that the Ray Rice penalty should have been stiffer, and the NFL's new penalties for domestic violence.
Cossack On NFL's New Domestic Violence Policy
ESPN legal analyst Roger Cossack discusses the NFL implementing severe penalties for domestic violence incidents.