BERKS COUNTY, Pa. (CBS) — There are disturbing new details in the deaths of two young siblings in Berks County. According to court documents, their mother found them hanging from a dog leash in the basement of an Albany Township house on Sept. 23.

Four-year-old Brinley Snyder and 8-year-old Conner Snyder were pronounced dead three days later at Lehigh Valley Hospital.

READ MORE: Stella The Pit Bull, Gloucester County Animal Shelter's Longest Resident, Adopted

Authorities say more forensic testing is needed before the autopsy report can be released.

READ MORE: 'This Is Do Or Die': Congressman Dwight Evans' Urgent Message For President Biden, Philadelphia Mayor Kenney On Gun Violence

The Berks County district attorney says this is only the beginning of a lengthy investigation and that they are interviewing everyone who knew the kids.

The father was not involved in the victims’ lives. Investigators believe this is an isolated incident and there is no danger to the community.

MORE NEWS: Candidate For Pennsylvania Governor Says He Did Not Cause Fatal Accident

So far, no charges have been filed.