A man allegedly stabbed his wife to death yesterday and then went to another house where he killed an elderly couple and two children, all family members, US police said.
Investigators said Mr Nikolay Soltys (27) killed his 27-year-old wife in the Sacramento suburb of North Highland.
Police said he chased her from their own home into the adjoining home of the duplex before stabbing her to death.
"The neighbor called police, who were investigating when news arrived of the stabbing at the second home in nearby Rancho Cordoba," said Sgt James Lewis of the Sacramento County Sheriffs' Department.
When they arrived they found the body of a 10-year-old child on the front porch and three other victims inside. The victims at the second location were Soltys's second cousins, Sgt Lewis said. "We have no idea as to motive," he added.
Sgt Lewis said one family member was unaccounted for - Soltys's three-year-old son. Witnesses told police they saw him at the first location, but he was not seen at the second home, he said.
Mr Soltys is originally from the Ukraine, and most residents of the poor, mostly Russian-speaking, neighborhood speak little or no English, complicating police efforts to investigate the crime.