Theobald "Theo" Lengyel, a founding member of the experimental rock band Mr Bungle, was convicted of the first-degree murder of Alice "Alyx" Kamakaokalani Herrmann at her California home on 4 December last year.

He faces life in prison and is set to be sentenced in November.

Lengyel, 55, was arrested in January after Ms Herrmann's remains were found in a wooded area of a park in Berkeley, California.

She had been reported missing the previous month after she didn't show up to a family gathering in Hawaii, with Lengyel named by police as a person of interest.

During the trial, prosecutors played an audio file recorded on Ms Herrmann's phone begging for her life as her boyfriend strangled her to death.

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

An official from the district attorney's office admitted that investigators did not discover the audio file until 22 September 2024 - one month after Lengyel's murder trial began.

The recording starts with Lengyel - also known as Mylo Stone - playing piano before growing angry at Ms Herrmann because she doesn't want to go out to play pool. Ms Herrmann repeatedly says she does not want to go because she has to work in Berkeley the next day.

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A few minutes into the argument, Lengyel can be heard threatening his girlfriend, saying: "I could mash your f***ing brain."

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