‘Beast’ convicted of ‘furry’ forbidden love triple murder sentenced in California: His accomplice was a ‘brony’

Content warning: This article describes murder and mentions child sexual abuse. Please take care while reading.

A California judge has ruled a man convicted of a 2016 triple-murder —motivated by parents’ disapproval of a love affair he had with a teenage girl he met through the “furry” subculture, or groups of people who enjoy dressing up in anthropomorphized animal costumes — will serve three consecutive life sentences behind bars.

The convicted murderer, 33-year-old Frank Sato Felix — who went by “Entey” in the furry community — called himself a “beast” at his sentencing hearing, according to The Orange County Register. Felix’s accomplice, Joshua Charles Acosta — who was 21 when the murders happened and who is reportedly a “brony,” a term for an adult man who is a fan of the My Little Pony franchise — is already serving a life sentence for his role in the crime.

The 2016 triple murder

Man gets life in prison without parole for Fullerton murders of trio with ties to ‘furry’ community

Frank Sato Felix committed the 2016 shotgun murders after becoming obsessed with the couple’s teenage daughter.https://t.co/0bCJDe8b77 pic.twitter.com/3qjTe6OMnb

— Tony Seruga (@TonySeruga) April 11, 2025

It all started in 2016, when Felix, then 25, met the 17-year-old Katlynn Goodwill, through the “furry” subculture and became romantically involved with her, a relationship her mother, Jennifer Goodwill-Yost, and her stepfather, Christopher Yost, strongly opposed. According to the Orange County District Attorney’s Office, Acosta, a 21-year-old Army private stationed at Fort Irwin, was also part of this community and became involved.

According to prosecutors, the motive stemmed from a plan to help Katlynn escape what she said was an abusive household. Katlynn testified that her stepfather had molested her for years and that she had informed Felix about the abuse. Acosta later told police he acted to “cauterize” what he described as a “festering wound” in the family.

On September 24, 2016, Acosta and Felix arrived at the Yosts’ home in Fullerton, California. Felix waited outside with Katlynn while Acosta entered the house armed with a shotgun provided by Felix. Acosta shot the Yost family friend Boucher as he slept on the couch, then killed Jennifer Yost in her bed, and finally shot Christopher Yost as he attempted to flee.

The next morning, the Yosts’ 6-year-old and 9-year-old daughters discovered the bodies and called 911. Katlynn and Felix had fled the scene, attempting to destroy evidence by burning their clothes and cell phones.

Katlynn’s current status is unknown

After the murders, Katlynn was detained by the authorities. Initially reported missing, she was later found unharmed and taken into custody at the Orange County Juvenile Hall in connection with the killings. Due to California laws protecting the privacy of juveniles, specific details about her legal proceedings and subsequent status have not been publicly disclosed.

Acosta was convicted in 2018 of three counts of first-degree murder with special circumstances and sentenced to life in prison without parole plus an additional 75 years. Felix was convicted in November 2024 on similar charges and sentenced in January 2025 to three life terms without the possibility of parole.

After Felix called himself a “beast” at his sentencing hearing, he said, “To the families and the victims, I would trade places in a minute with those who were killed.” One of Yost’s sisters who discovered her family and her family friend dead, told the court, “No sentence can erase the horrors of that night.”

Orange County District Attorney Todd Spitzer said in a statement, “Two little girls, six and nine, went to sleep not knowing the last time they would see their parents would be when they woke up to find them shot to death.”

Spitzer added, “The trauma inflicted on those little girls compounded by the loss of both of their parents in such a violent way is beyond heartbreaking. Violence is never the answer and a sick and twisted plan turned into life behind bars for two young men.”

If you know someone suffering from sexual violence, contact RAINN or the National Sexual Abuse Telephone Hotline at 1-800-656-4673.