Green and Kristiansen told police the infant's father left the apartment and they did not know the child died, authorities said.
The father, identified as 31-year-old Lamont Bacchus of New Castle, Delaware, was later found by police. All three of the people involved were arrested for endangering the welfare of children and criminal conspiracy.
Police say there was at least an hour and a half delay between anyone discovering the deceased child and calling for medical assistance. The investigation revealed that during that time Kristiansen delivered 10 bags of heroin to Green and Bacchus, and cleaned the scene before calling for police.
The investigation also found that Bacchus had physically assaulted Green earlier that morning, police said. Bacchus is also charged with simple assault in addition to the endangering the welfare of children and criminal conspiracy charges.
Police say when they arrested Bacchus, he was in possession of three bags of heroin and is being charged with possession of a controlled substance.
Officials report that Kristiansen's 8-year-old daughter was also living at the Barrett Township apartment but was removed before police were alerted.
All three people involved were taken to the Monroe County Correctional Center and are awaiting arraignment.
Green also has additional warrants for her arrest from the Stroud Area Regional Police and Monroe County Sherriff's Office that she will be held on at the Monroe County Correctional Center.
Three in Barrett Twp. arrested, charged in connection with death of two-month-old baby