A lethal mix of heroin and cocaine killed Layne Staley, lead singer of defunct grunge band Alice in Chains.
Staley was found dead in his Seattle home last month.
An autopsy listed the drug overdose as accidental, ruling out homicide or suicide in the death of the 34-year-old.
The examination also determined that Staley had been dead two weeks when police officers were called to his home.
Staley co-founded Alice in Chains in 1987 with guitarist Jerry Cantrell.
