LOS ANGELES (AP) – Homicide detectives investigating the slaying of a NASA engineer, a woman and two children stabbed before they were burned in a Mojave Desert house fire named two "persons of interest" in the case.

Detectives want to talk to Si Young Yoon of Lancaster and Jae Hwan Shim of Palmdale, Los Angeles County sheriff's Sgt. Howard Cooper said Friday.

The two were last seen leaving their homes Monday, the same day the bodies of 60-year-old NASA engineer Joseph Paul Ciganek, a woman, a boy and a girl were found at Ciganek's house in Quartz Hill.

Cooper says Yoon and Shim have connections with people who lived at the burned home, but would not elaborate.

The four victims were beaten and stabbed to death before the fire, Los Angeles County coroner's spokesman Ed Winter said Thursday.

Ciganek worked at NASA's Dryden Flight Research Center at Edwards Air Force Base, a spokesman for the agency said.

Authorities did not release the names of the other three victims but said they were relatives of Ciganek's wife, Jocelyn, who was returning home from work at the time the fire broke out and was not among the dead, authorities said.

Quartz Hill is an unincorporated area near Lancaster in the Mojave Desert north of Los Angeles.

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