MARTINEZ, Calif. -- Having been trained as a SWAT officer, Paul Starzyk knew when he heard the screams of children he had to act quickly.

Authorities said Starzyk and fellow officer Ian Leong were called to the Elegant Hair Design on Pacheco Boulevard in Martinez at about 11:30 a.m. Saturday.

The officers quickly searched the salon for the reported gunman and then moved on to back apartment e when they hear cries for help. They stood in a narrow hallway leading to the second-floor apartment, preparing to storm in when shots rang out.

Felix Sandoval allegedly poked a hand out from behind the door and opened fire, blindly, with a .38-caliber revolver. Starzyk was wearing a protective vest but a bullet found its way passed the vest and killed the officer.

"What we had was trained officers determined to attempt to save lives, and they put their own lives in jeopardy," Martinez Police Chief Tom Simonetti told the San Francisco Chronicle. "Unfortunately, it's a one-in-a-million shot, and the suspect managed to hit Sgt. Starzyk."

Sandoval was shot dead by a third officer who responded to the apartment and police then found the body a 44-year-old woman -- Catalina Torres, a cousin of Sandoval's estranged wife, dead in the kitchen.

A joint investigation was ongoing and the sheriff's office and the Police Department was continuing to collect evidence, get a better idea of the chain of events, according to sheriff's spokesman Jimmy Lee.

In honor of Starzyk, flags at the state Capitol were being flown at half-staff today.

"The Martinez Police Department is a small Police Department. It is a place where everyone knows each other. It is a tough time for them," Lee said.

California Gov. Arnold Schwarzenegger released a statement Sunday saying he and his wife Maria were deeply saddened to learn that Martinez police Sgt. Paul Starzyk was killed in the line of duty in the city this weekend.

"The people of California are forever indebted to Paul's tireless service and we will never forget his selfless dedication to public safety," Schwarzenegger said in a prepared statement. "Maria and I send our thoughts and prayers to Paul's family, friends and fellow officers as they mourn this tremendous loss."

Starzyk was a 12-year veteran of the Martinez Police Department. He leaves behind his wife and three small children.