CHICAGO (CBS) — A letter from Francis Cardinal George on sex abuse cases by Chicago area priests will appear in church bulletins throughout the Archdiocese on Sunday.

The letter contains an apology and a plea from Francis Cardinal George to Chicago area parishioners as attorneys prepare to release documents detailing sexual abuse by 30 priests.

CBS 2 Chief Correspondent Jay Levine has obtained the letter to be read at mass this week.

The names of nearly all 30 priests guilty of sexual misconduct have been listed on the Archdiocese website for years. Just three of them, who’d died before allegations against them surfaced, are new, as is the Cardinal’s most complete explanation yet, a personal defense of the one which occurred on his watch.

It’s the case of Daniel McCormack, now defrocked and in state custody for molesting young parishioners on the West Side. McCormack was allowed to return to his parish after being arrested in 2005 because, the Cardinal writes, “various offices involved did not consistently share what they knew with each other or with me.”

“no one involved in investigating the allegation, not even the review board …told me they thought he was guilty.”

The Archdiocese has already paid out millions of dollars in settlements to McCormack’s victims.

In an interview last month reflecting on his 50 years as a priest, he was clearly referring to the McCormack case when he told Levine, “I regret some things, other things with grace of God have gone well. You’re very dependent on other people. You have to determine whom can you trust, and that’s not always easy.

“There was this history in Chicago don’t tell the Cardinal that goes back a long time and that, practically killed us in a few cases. “

In the letter titled Accountability and Transparency, the Cardinal writes, the new revelations will be “helpful…for some, but painful for many.” Especially for the victims, as he said on Chicago Tonight.

“It’s a delicate thing. It’s taken us years to negotiate with the plaintiff’s lawyer who respects that also you don’t want to re victimize victims but nonetheless the stories are there in a general way and sometimes rather specific,” said Cardinal George.

And he concludes by saying “I apologize to all those who have been harmed by these crimes and this scandal…(and) shamed by the actions of some priests and bishops.”

The letter is not only a preemptive strike aimed at framing the details from court documents about to be made public, But also the Cardinal’s personal attempt to set the record straight on the McCormack case and its impact on his legacy. “A mistake,” he calls it, “not a cover-up.”