Four people including a NASA engineer were beaten and stabbed to death in the engineer's Mojave Desert home, which was then set afire, authorities said.
The badly burned remains of engineer Joseph Ciganek, a woman and two children were discovered Monday in the ashes of his home in an unincorporated area near Lancaster, north of Los Angeles. Ciganek's wife, Jocelyn, was returning from work at about the time the fire broke out, authorities said.
The fire had been labeled suspicious, and on Thursday authorities confirmed the four had been killed before the fire was set. Sheriff's homicide detectives are investigating.
"We believe the burns did not contribute to the death, that they were killed prior," Los Angeles County coroner's spokesman Ed Winter said.
Authorities did not release the names of the other three victims but said they were relatives of Ciganek's wife. The woman and the older child, a girl of about 13, were stabbed to death, Winter said. Ciganek and the other child, a boy of about 10, were beaten and slashed.
Neighbors said Ciganek, 60, and his wife had lived in the house for at least 13 years.
Ciganek worked at NASA's Dryden Flight Research Center at Edwards Air Force Base, a NASA spokesman said.