Raymond "R.C." Horsch cooperated with feds in 2012 on narcotics, crimes against children cases, documents show

Newly unsealed court documents reveal Raymond "R.C." Horsch cooperated with federal authorities and the U.S. Attorney's Office in Philadelphia 14 years ago regarding outstanding narcotics and financial crimes cases and crimes against children.

The information came to light after the Philadelphia Inquirer fought to lift the seal on several judicial documents concerning Horsch. U.S. District Judge Paul S. Diamond on Thursday granted the newspaper's request in part.

Horsch was facing sentencing at the time in July 2012 on allegations that he had a large marijuana grow in the basement of his home in Chalfont, Bucks County.

Horsch's deal, which was hidden from the public until Thursday, earned him a lighter sentence with some of the charges dropped.

An assistant U.S. attorney said Horsch's information on drug trafficking and crimes against children was found to be credible and reliable but dated. It's unclear if Horsch's cooperation ever resulted in the prosecutions of others.

A prosecutor wrote that Horsch, who is now being investigated as a serial killer according to multiple sources, had a long history of criminal conduct.

More documents may be unsealed as the judge continues his review.

A spokesperson for the U.S. Attorney's Office declined to comment.

The FBI and Philadelphia wrapped up work at the "house of horrors" in the city's Olney neighborhood on Oct. 23. Investigators were searching for evidence of human remains at the home at 417 W. Chew Ave. owned by Horsch and his son, Eugene Horsch.

Eugene Horsch remains in custody pending trial on firearms and other offenses.

Bones were found in the property's backyard on Oct. 15, but further testing revealed they were animal bones.  

Stay with CBS News Philadelphia for ongoing coverage of this investigation and follow on YouTube for extended "House of Horrors" coverage every Friday.