Assuming a posture of contrition and humility, the leaders of the U.S. Roman Catholic church moved Thursday toward adopting toughened policies that would remove from ministry any priest who abuses a child, even for a single allegation from long ago.

In a historic session Thursday, sexual abuse victims addressed all 300 of the nation's bishops, including many men who protected priests who were abusers.

And in perhaps the strongest words yet from the church, the leader of the bishops apologized to victims and to all Catholics for what the hierarchy had allowed to happen.

"In my own name and in the name of all of the bishops, I express the most profound apology to each of you who have suffered sexual abuse by a priest or another official of the church," said Bishop Wilton Gregory of Belleville, Ill., president of the U.S. Conference of Catholic Bishops. "I am deeply and will be forever sorry for the harm you have suffered. We ask your forgiveness."

With the wounded victims before them, the powerful leaders of the nation's largest Christian denomination appeared chastened.

At one point during the closed door meeting, Cardinal Bernard Law apologized personally to Bishop Gerald Barnes of San Bernardino, Calif., for allowing Rev. Paul Shanley to be moved to Barnes' diocese even though officials knew of sex abuse allegations against him. A spokeswoman for Law said the cardinal intended to apologize more broadly to all the bishops later Thursday.

The shift in moods of the church leaders was reflected in the evolving policy discussions going on behind closed doors late into the night. Some bishops had once advocated more forgiving rules but became painfully cognizant by this week of the scope of repair that Catholic Americans expect.

By Thursday afternoon, the bishops had rewritten an earlier draft to set a strict zero-tolerance policy, Cardinal Francis George of Chicago said after emerging from an executive session. Although a formal vote will not come until today, "the sense of the policy is that if this sin -- even if it's no longer a crime in civil law -- is in a priest's experience, then we should take him out of ministry," George said.

The injuries caused by abuse, and by the protection of abusers, were again made terribly real to bishops Thursday.

Between tears and choked pauses, Craig Martin told row after row of men in black about the years of silent pain -- and sexual compulsivity and alcoholism -- that followed his molestation by a priest at age 11.

"Gentlemen, I wanted so desperately to be heard," the 46-year-old Minnesota man said. "I wanted someone to listen to me. I wanted someone to help me. I wanted to break the silence and despair that was killing me."

Martin was one of four people to describe to the silent room of bishops stories of molestation and of the psychological, spiritual and physical tolls that followed.

"We were moved profoundly," said Gregory. "We felt their agony."

The emotional meeting marked a public departure from the often antagonistic relationship between bishops and victims. They have taken opposing sides in political and legal fights, and, as recently as the weekend, had argued about which victims would be allowed to speak at the conference.

But here, both sides had reasons to stand together: The bishops hoped to quiet critics who say they have sided with the needs of priests over victims; the victims, meanwhile, hoped to sway the bishops to adopt the strictest possible national sex abuse policy.

Gregory said the bishops assume broad responsibility for their failings, and, though they could not change the "robbery" of the childhood and innocence of the four victims they heard from, they have pledged to protect children in the future.

He called on all victims, priests and bishops to report any cases of abuse that haven't been exposed -- saying he hopes clerics will come forward and report themselves.

"We are the ones, whether through ignorance or lack of vigilance, or -- God forbid -- with knowledge, who allowed priest abusers to remain in ministry and reassigned them to communities where they continued to abuse," Gregory said. "We are the ones who worried more about the possibility of scandal than in bringing about the kind of openness that helps prevent abuse."

But by nightfall, it was unclear what punishments, if any, the bishops will set for their own acknowledged failures to prevent abuse. Some leaders, most notably George, have said bishops must be penalized if priests are, but language to that effect had yet to be worked out in the proposed policy, he said.