A 49-year-old Hayward man who sexually assaulted a woman during a massage at a Millbrae spa was convicted Friday, Aug. 14, of two felonies and a misdemeanor, marking his second sex crime conviction in three years.

Guosheng Chen was found guilty of sexual penetration by force or fear, oral copulation by force or fear and misdemeanor sexual battery for an attack on a female client at Water Lounge Spa on Dec. 22, 2024, the San Mateo County District Attorney's Office said on X.

The investigation began after the victim contacted the San Mateo County Sheriff's Office the same day she was assaulted, according to Patch. She went directly to a hospital after leaving the spa.

The woman had booked an appointment with her regular therapist, but that person was unavailable and Chen was assigned in their place, prosecutors said. The victim told investigators she specified the only areas on her back Chen could touch. As the session continued, Chen began making noises and touched the victim's private areas, including reaching beneath her underwear, according to the DA's office account reported by KRON4. The woman froze, then left.

Investigators identified Chen as the therapist and obtained an arrest warrant. He was taken into custody Jan. 2, 2025, with assistance from Hayward police and booked into the Maguire Correctional Facility.

Chen had previously been convicted of sexual battery in 2023. The jurisdiction of that earlier conviction was not disclosed.

The Sheriff's Office said Chen worked as a massage therapist across San Mateo, Alameda, Contra Costa and San Diego counties. Investigators believe there may be additional victims who have not come forward.

Chen remains in custody on $400,000 bail. Sentencing is scheduled for Tuesday, Sept. 8.

Anyone with information about Chen or potential additional incidents can contact the San Mateo County Sheriff's Office anonymous tip line at (800) 547-2700. The DA's Victim Services Division offers free support to crime victims regardless of immigration status.