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Joseph Ciganek, 60 years old, a 34-year-old woman, and two children slashed and beaten to death were found inside a house that was set on fire. The incident happened last week.
Two suspects were arrested over the weekend and have been formally charged with murder. L.A. County prosecutors filed charges Tuesday against 39-year-old Jae Hwan Shim, and 27-year-old Steve Kwon. Both were arrested Saturday in Arizona near the Mexican border.
Prosecutors say Shim killed his ex-wife and her two children and the ex-wife's cousin's husband, a NASA engineer last Monday, then set the house on fire in Quartz Hill.
Tuesday, L.A. County Sheriff's detectives asked for the public's help in finding 34-year-old Si Young Yoon. Yoon was dating the suspect's ex-wife. Yoon has been missing since the day of the murders.
"Investigators are concerned for Mr. Yoon's welfare, and believe that he may be the victim of foul play," said Lt. Dave Coleman, L.A. County Sheriff's Dept. "His vehicle was recovered last Saturday, June 28, 2008, but he is still missing."
Detectives are worried that perhaps something has happened to Yoon, and they're looking for any information related to the case. Police found Yoon's Acura SUV Saturday, but they are looking for a gold Mercedes that he was driving. That car is still missing, along with the owner.