Sheriff's spokesman Sgt. Don Morrissey said today that sheriff's deputies are working with police in Los Angeles County to track down suspect Huaichang Zhao of Fremont.
He is believed to be in Monterey Park, Morrissey said, or Los Angeles' Chinatown area. The sheriff's office also has sent its own investigators to Monterey Park, Morrissey said.
Authorities believe Zhao, 45, was performing landscape work for the victims when the assault occurred in their home on Berry Court. The attack left Wei Wei Li, 42, dead. Her husband, who is 42, is still in the hospital being treated for injuries classified as serious but not life-threatening.
The couple's two young children witnessed the attack, Morrissey said, and the daughter called 911 to report the assault. They were not injured and are in protective custody in a safe location.
Authorities believe Zhao fled in a 2008 white Ford F150 pickup truck and then caught a ride with a friend to Los Angeles County.
"We don't know the motive for going down there," Morrissey said. "We don't believe there's family down there, but it could possibly be because there's a large Asian population in Monterey Park."
Zhao is described as about 5 feet 7 inches tall, weighing about 200 pounds.
Anyone with information on his whereabouts should call Sgts. Binder or Lera with the sheriff's office investigations division at (408) 808-4500 or use the anonymous tip line, (408) 808-4431.