Both will be sentenced May 29.
Charges were not filed against Fordyce and Plum until nearly five months after Jeremiah Hoffman, 23, was found dead in his bedroom by his father on the morning of Feb. 3, 2001, according to court records.
Franklin County Coroner Jeffrey Conner told police Hoffman died as a direct result of a heroin overdose, records show.
Police collected drug paraphernalia, suspected heroin and other items from Hoffman's bedroom, court records said.
State police spoke with Travis Dickinson, no age or address available, who said he met Hoffman at a bar in Greencastle early Feb. 3.
The two had several beers before Hoffman followed another man, described in court records as Plum, into the restroom, Dickinson told police. Hoffman followed Plum out of the bar at 2:15 a.m., telling Dickinson they were going to get some cocaine, court records alleged.
Dickinson and Hoffman followed Plum to an apartment building in Greencastle, which Hoffman entered for about 10 minutes, according to court records.
Plum told police he and Hoffman "did a line" of heroin together. He said he gave the rest to Hoffman, who then left, court records said.
Police interviewed Fordyce a month after Hoffman's death. She told police she gave Plum the heroin that he and Hoffman shared, according to the affidavit.
Plum is free on $25,000 bail. Fordyce was returned to Franklin County Prison in February after police found suspected drugs in her vehicle. She was charged with possession with intent to deliver heroin and conspiracy to deliver heroin.