MONROE COUNTY, Ind. — The Monroe County Coroner has released the cause of death of a 20-year-old Indiana University student who was found dead on the morning of August 17.

Avery McMillan died as a result of fluorofentanyl and fentanyl toxicity, Coroner Joani Stalcup concluded. Meaning McMillan died as a result of fentanyl.

Previously, the Monroe County Sheriff’s Department announced the arrest of 33-year-old Eric Montgomery in connection to McMillan’s death. He is charged with one count of felony rape and another felony count of furnishing alcohol to a minor.

Court documents state that McMillan was found unresponsive in a room of a house where Montgomery lived. During conversations with detectives, Montgomery reportedly admitted to having sex with McMillan in a city parking garage and again in his home.

Booking photo of Eric Montgomery

Montgomery also told police that he and McMillan smoked marijuana and drank alcohol that he provided to her, per court documents.

Court documents revealed that McMillan had been at a house party prior to winding up in Montgomery’s home. A roommate told detectives McMillan had “got a little more drunk than she intended or wanted to” and ended up exiting a vehicle that left the house party and refused to get back inside her roommate’s car.

Surveillance footage puts McMillan in the parking garage of her apartment complex between the hours of 2:19 a.m. and 4:02 a.m.

According to the sheriff’s department, Montgomery has a “violent and extensive criminal history.” He was arrested during a traffic stop without incident with the assistance of the Critical Incident Response Team.