The musician, born Paul Frehley, passed away in Morristown, New Jersey, last month at the age of 74. At the time, a representative said his death was due to “a recent fall at his home,” but no further details were provided until now.

The medical examiner’s report states that a CT scan revealed several contusions and bone fractures to the back of Frehley’s skull, along with hemorrhages and a subdural hematoma, a type of bleeding that occurs in the brain after a severe head injury. Additional bruises were also found on his hip, thigh, and abdomen. The report further noted that Frehley had experienced a stroke.

According to TMZ, Frehley was placed on life support after the fall, and he passed away when his family made the decision to remove him from the ventilator. The report also indicated that doctors attempted a hemicraniectomy, a surgical procedure designed to relieve pressure from the hematoma.

Frehley was a founding member of KISS and played with the band from its early days in 1973 until 1982, leaving due to substance-abuse struggles and creative disagreements, particularly with Gene Simmons and Paul Stanley. He later reunited with KISS for their 1996 reunion tour but left again in 2002. All four original members performed together during their 2014 Rock & Roll Hall of Fame induction, and their final performance as a group took place in 2018. Frehley had been expected to attend this year’s Kennedy Center Honors, where KISS is being celebrated.

“No one can touch Ace’s legacy,” Simmons wrote after Frehley’s passing. “I know he loved the fans. He told me many times … Ace was the eternal rock soldier. Long may his legacy live on!”

After parting ways with KISS, Frehley went on to enjoy a successful solo career as both a performer and recording artist. His final concert took place on September 5 in Providence, Rhode Island. Later that month, he canceled a scheduled appearance at the Antelope Valley Fair in Lancaster, California, following another fall at his home, and the next month, he canceled all remaining tour dates due to “ongoing medical issues.”

Frehley’s funeral was held on October 23 in the Bronx. His longtime friend and SiriusXM host Eddie Trunk said he received permission from Frehley’s family to organize a “tribute show/fan celebration at some point,” though no official plans have been announced.