ST. LOUIS (AP) -- St. Louis Archbishop Robert Carlson says mistakes he made in the 1980s when he investigated a man who emerged as one of the country's most notorious pedophile priests have shaped the way he deals with sexual abuse cases.

The St. Louis Post-Dispatch reported Saturday that the results of its review of several hundred internal church documents and transcripts of testimony showing Carlson's involvement in the case of defrocked priest Thomas Adamson.

Carlson investigated Adamson while handling clergy misconduct cases for the church in the 1980s.

The Post-Dispatch reported that Carlson confronted Adamson in December 1980, after hearing a rumor that he had grabbed the genitals of an eighth-grade boy in a YMCA whirlpool. Adamson admitted to the abuse but said it was an isolated incident. Carlson said he should resign or face suspension.

But the late Minnesota archbishop John Roach disagreed and eventually allowed Adamson to be reassigned to other churches, where others were abused.

Carlson objected but didn't go to authorities -- something he described as "a mistake."

At one point, Roach took Carlson off the Adamson case, saying he thought Carlson was too angry with Adamson to be objective.

But in the summer of 1984, Carlson received a phone call about another accusation involving Adamson at two archdiocesan parishes from 1978 to 1982. Roach put Carlson back on the case.

Adamson admitted the abuse and "agreed that it probably would be first-degree criminal sexual contact," according to a memo Carlson wrote to Roach.

But Carlson didn't go to police. Instead, in the same memo, Carlson recommended that "given the seriousness of our exposure that the Archdiocese posture itself in such a way that any publicity will be minimized."

Later that year, the archdiocese finally acknowledged the reality that Adamson's crimes were going to be made public.

Adamson, who eventually was defrocked, admitted in a deposition to abusing children in 10 of the 13 parishes in which he was placed by his bishops. The Post-Dispatch reported that by one estimate, Adamson abused at least 35 minors over 24 years.

Carlson's handling of the case is a subject of debate. Some say reporting the allegations to authorities could have derailed his career and that sexual abuse was not widely reported at the time. But others were less sympathetic.

Jeffrey Anderson, a lawyer in St. Paul who has represented dozens of victims of clergy sexual abuse in Minnesota, said Carlson "was active in the concealment and the deception, and the deceit of the police, the public and the parishioners."

Regardless, Carlson acted on lessons he learned from his time in Minnesota when the abuse crisis broke nationally in 2002.

The Rev. Kevin McDonough, a priest in the archdiocese of St. Paul and Minneapolis, said Carlson "went to school on the failings" with Adamson.

"When (Carlson) learned the lessons that that terrible situation taught, he became a ferocious advocate for the church cleaning house," said McDonough, who has coordinated the archdiocese's response to clergy misconduct since 1990. "And he's remained that way."

While bishop of the diocese in South Dakota, he called the state's attorney general and offered to open up the church's files.

Carlson's efforts have included requiring that priests who come into his dioceses from the outside as well as other diocesan workers undergo local, state and national background checks.

In St. Louis, Carlson said he will review the systems already in place for training, background checks and "norms of conduct." He said he went through the file of every priest when he arrived in Saginaw, Mich., in 2005 to serve as bishop there.

"You gotta know who you've got," he explained.

And he said he plans to do the same thing in St. Louis.

"It'll take a little longer," he said. "But yes. Absolutely."

(Copyright 2009 by The Associated Press. All Rights Reserved.)