Riley Gale, the vocalist for Texas metal band Power Trip, died last year at age 34. At the time, his cause of death was not revealed. In an interview with Stereogum last December, Power Trip collaborator Ice-T suggested Gale’s death was opioid-related. Now, as MetalSucks points out, the Dallas County Medical Examiner’s office confirms Gale died from a fentanyl overdose.

According to Gale’s autopsy report, he died from pulmonary edema, which is caused by excess fluid in the lungs. The condition was a result of “the toxic effects of fentanyl.” His blood contained 22.5ng/mL (nanograms per milliliter) of fentanyl at the time of his death, over the recommended dosage for both analgesia and anaesthesia. The autopsy report noted Gale’s “history of Xanax abuse” and “history of depression” and declared his death an accident.