According to a press release from the Orange County District Attorney's office (and I'll warn you that it includes graphic details), the State of California linked Son to the crime when a DNA sample provided after an unrelated conviction for felony vandalism matched DNA taken from the scene and the victim in 1990. The Huntington Beach Police Department took Son into custody shortly thereafter.
Son fought four times under MMA rules, and is most known by MMA fans for his UFC 4 bout against Keith Hackney. He also appeared as Kimo Leopoldo's manager at UFC 3.
Son also appeared in seven movies during the mid-1990s, including playing henchman Random Task in the first Austin Powers movie.