On September 7, the 26-year-old rapper, who famously dated singer Ariana Grande, was found dead in his Studio City, California, home.
The Los Angeles County Department of Medical Examiner-Coroner ruled in a statement released Monday that Miller’s death was accidental and due to mixed drug toxicity - citing an accidental overdose of fentanyl, cocaine and alcohol.
PEOPLE were advised by Los Angeles County coroner’s spokeswoman Sarah Ardalani that the autopsy was completed three days after the star’s death and his body was released to his family, who have since buried him in their hometown of Pittsburgh.
The coroner's report shared upsetting details about how Miller was discovered.
The musician was found on his bed, “kneeling with his face resting on his knees” by his personal assistant.
They tried to get help by calling 911, before moving Miller to the floor where he performed CPR until emergency services arrived and pronounced the rapper dead.
The assistant later told authorities that Miller “struggles with sobriety and when he ‘slips’ he consumes them in excess,” adding that the musician had had “several recent ‘slips,'” the most recent being three days prior to his death.
The night prior to his passing, Miller was with his friends, where they spent the evening watching football.
He had just released his fifth and final studio album Swimming.
In a 2016 short documentary by music magazine The Fader, Miller spoke about why he relied on substances like codeine-based cough syrup mixed with soda.
“It started by me just sitting inside all day and then it’s like, then you get bored. Then you’re like, ‘Well I could just be high, and I could have a whole adventure in this room,’ ” the “Self Care” rapper began. “I’m always like, if someone’s like, ‘You wanna try this?’ I’m like, ‘Yeah sure.’ It f—s you up when you have a bunch of money because you try a drug, you like it, then you can buy a lot of it. I went through about everything.”