April 15, 2008 -- Even as he told reporters on his flight to America that he was "deeply ashamed" over the church sex abuse scandal, Pope Benedict was accused by victims of protecting some 19 bishops accused of sexually abusing children.

"As a Catholic, I have to sadly conclude that he is not serious about ridding the church of corrupt bishops," said Anne Doyle, co-director of BishopAccountability.org, a group tracking public records involving the bishops.

According to the group, of the 19 bishops "credibly accused of abusing children," none has lost his title, been publicly censured by the Vatican or referred for criminal prosecutions.

"The sexual corruption in the Catholic church starts at the very top," said Doyle.

Pope Benedict told reporters on his flight this morning from Rome to Washington, D.C., he would do everything possible to avoid a repeat of the scandal. "We will absolutely exclude pedophiles from the sacred ministry," he said, according to Reuters.

While the church has moved to expel accused priests, critics say the higher-ranking bishops have been given favored treatment. "The attitude of the bishops towards the victims and the families of sexual abuse and predatory clergy is drop dead," said Michael Wegs, of Marion, Iowa, one of nine former high schools students who said they were abused at a seminary in Missouri by former Palm Beach, Fla. Bishop Anthony J. O'Connell.

When the allegations were made public, Bishop O'Connell admitted at least two cases of abuse and was allowed to resign. He now lives on the beautiful, sprawling grounds of the Trappists Mepkin Abbey in South Carolina.

"He deserves to be in jail," said Wegs, his accuser. "I don't think there is any justice because he is allowed to travel, go where he please. He's still a bishop, and he's living among priests in the hierarchical structure; he is a top dog despite the fact that he's a sexual predator." Wegs says O'Connell has failed to even apologize to his victims.

Bishop O'Connell did not return phone calls from ABCNews.com seeking comment, but church officials say he and other bishops have been punished appropriately. "You cannot put on clerical attire, and you cannot service in a public way in ministry," said Austin, Texas Bishop Gregory Aymond, chair of the U.S. Bishop's Committee on Protection of Children and Young People.

"That is a very, very significant consequence, and I would say a significant penalty," said Bishop Aymond, who conceded the accused bishops maintain their title. "Priests and bishops remain priests and bishops forever, regardless of what happens to them or what they do," said Bishop Aymond.

But victims groups and church critics say the pope can and should do much more to punish the bishops and finally resolve the scandal.

Before he became pope, as Cardinal Joseph Ratzinger, he was in charge of monitoring cases of pedophile priests and was directly involved in deciding what punishment, if any, would be administered to priests and bishops.

"Priests who abuse children can be removed from the priesthood, but they do not remove bishops, they do not remove cardinals," said author Jason Berry who has been tracking the sex abuse scandal and produced a documentary film on the subject, "Vows of Silence," which premiered in New Orleans last night. "The problem is the power structure. There is no accountability," said Berry.

Berry says the pope's decision to have the Los Angeles archbishop, Cardinal Roger Mahoney, accompany him on his trip proves the point. "Why would you want someone in your entourage" like Roger Mahoney, asked Berry.

"This man has overseen a great many cases in which priests were moved from parish to parish. His diocese has paid over $660 million in settlements. And yet this cardinal has refused to release the files on these priests who have abused children," Berry said.

Cardinal Mahoney did not return calls from ABC News seeking comment.

Click Here for the Investigative Homepage.