SAN RAFAEL, Calif. (AP) — A gunman opened fire Monday inside a California rehab center that treats addicts who also have psychiatric problems, killing a man and wounding two others before fleeing, authorities said.

Detectives said they were aware of the shooter's identity, but would not release the person's name because of the ongoing investigation. A possible motive was not disclosed.

Deputies who responded to calls that employees at the Helen Vine Detox Center in San Rafael had been shot found three victims — two men and a woman, Marin County Sheriff's Sgt. Michael Brovelli said.

The detox center says on its website it treats people with alcohol and drug addiction and "co-occurring psychiatric problems."

The wounded victims were taken to Marin General Hospital, but their identities were not released to protect the investigation, Brovelli said.

Neither he nor a hospital spokeswoman immediately provided information on the condition of the two people who were wounded.