Suspected serial killer Raymond Horsch put himself in "great degree of danger" as informant, court papers say

In a newly unsealed document from 2012, a lawyer for Raymond "R.C." Horsch wrote to the court that Horsch had exposed himself to a "great degree of danger" while cooperating for the federal government as an informant.

Judge Paul Diamond last week granted a motion filed by the Philadelphia Inquirer to lift the seal on previously secret judicial documents in Horsch's drug trafficking case from 14 years ago.

Horsch, who died last year, is being investigated as a suspected serial killer — that's according to numerous law enforcement sources with direct knowledge of the case.

Some seven missing women are connected to his former residence on Chew Avenue in the city's Olney neighborhood, a home that's been referred to as the "house of horrors."

No human remains have been found at the house, but detectives have looked for evidence of wet cremation, which is when a mix of chemicals is used to break down human remains, law enforcement sources with direct knowledge of the case told CBS News Philadelphia. Chemicals and pipes have been removed from the property during the investigation.

Court records released Tuesday detail more about Horsch's past dealings with federal prosecutors.

"While incarcerated, he [Horsch] engaged in some dangerous cooperative activities," Jerome Brown, the lawyer, wrote in a presentence memorandum in 2012.

Records unsealed last week described Horsch's cooperation and information he provided to the feds on drug trafficking and crimes against children as credible and reliable, but dated.

More records are expected to be unsealed in the coming days.

Brown, who today represents Horsch's son Eugene, has largely declined to comment on his representation of Raymond Horsch. He has confirmed ongoing negotiations with federal prosecutors to reach a plea agreement concerning firearms offenses and other charges filed against Eugene Horsch.