SANTA CRUZ, Calif. (AP) — A founding member of the experimental rock band Mr. Bungle was found guilty Friday of first-degree murder in the killing of his girlfriend after prosecutors in California found an audio file the victim recorded on her phone as she fought for her life.

A jury in Santa Cruz deliberated for a day before finding Theobald “Theo” Lengyel guilty of first-degree murder in the killing of his girlfriend Alice “Alyx” Kamakaokalani Herrmann on the night of Dec. 4, 2023, inside her Capitola home, KSBW-TV reported. Lengyel faces life in prison and is set to be sentenced in November.

Lengyel, 55, was arrested in January after investigators found Herrmann’s remains in a wooded area of Tilden Regional Park in Berkeley. Herrmann was reported missing the previous month after she didn’t show up to a family gathering in Hawaii.

On Oct. 1, prosecutors played an audio recorded on Herrmann’s phone begging for her life as her boyfriend strangled her to death, KRON-TV reported.

It is unclear if Herrmann, 61, intentionally recorded the audio or if the app inadvertently recorded it.

District Attorney’s Office Inspector Steven Ryan testified that investigators did not discover the chilling audio file until Sept. 22, 2024, a month after Lengyel’s murder trial began.

The recording starts with Lengyel playing piano before growing angry at Herrmann because she doesn’t want to go out to play pool. Herrmann repeatedly says she does not want to go because she has to work in Berkeley the next day.

A few minutes into their argument, Lengyel can be heard threatening his girlfriend stating, “I could mash your f***ing brain.”

According to prosecutors, the verbal argument escalated into a physical altercation. Herrmann could then be heard pleading for her life, gasping for air.

Lengyel left Mr. Bungle in 1996 after playing saxophone, clarinet and keyboards on several recordings, including the band’s self-titled 1991 debut album and “Disco Volante” in 1995. He did not participate in any of the band’s recent reunion tours, which began in 2020.

Mr. Bungle was formed in Northern California’s Humboldt County in 1985 by high school friends including guitarist Trey Spruance, bassist Trevor Dunn and vocalist Mike Patton, who went on to perform with Faith No More. Mr. Bungle experimented with funk, heavy metal, electronic, jazz and other musical styles, gaining popularity during the alternative rock boom of the 1990s.

In a 2005 Q&A, Dunn said Lengyel left the band on bad terms, SF Gate reported.