Police Ask Public’s Help to Solve Family’s Slaying : Investigation: Authorities seek witnesses, motives and solid leads in the 1991 stabbing deaths of a couple and their two young children.

Still baffled by a case described as “one of the most brutal” unsolved slayings in Los Angeles, police appealed to the public Monday for information that could help solve the 1991 murders of four family members in Granada Hills.

Investigators said they have little new information about the stabbing deaths of Hee Wan Yoo, his wife, Gyung Jin, and their children, Pauline, 6, and Kenneth, 4. But for the first time, authorities said they believe that more than one person was involved in the slayings.

Although Los Angeles police remained tight-lipped about the evidence in the case, they were candid about what they don’t have: witnesses, motives and solid leads.

“There was no rhyme or reason to these killings,” LAPD Detective Richard (Buck) Henry, who heads the investigation, said at a news conference at Parker Center.

The bodies of the family members were discovered Nov. 20, 1991, in the Yoos’ Granada Hills home by relatives who went to the house when Hee Wan Yoo failed to show up for work at the Wilshire-area dental lab he owned.

An autopsy concluded that each family member was stabbed with a sharp weapon, but county coroner’s officials declined to elaborate. Investigators have said there was no evidence of forced entry into the house.

Since the killings, police have conducted hundreds of interviews on the case and have employed up to six Korean-speaking officers in hopes of drawing information from the city’s Korean community, said Lt. Al Moen, head of the department’s major crimes division.

The case is “baffling because of the lack of evidence,” he said.

Police for the first time Monday said they have evidence that more than one person was in the house during the slayings. But they would not elaborate.

“We don’t know what occurred inside that residence,” Henry said. “We don’t know if we had suspects or witnesses in that residence.”

A $50,000 reward has been posted for information leading to the arrest and conviction of the killers. Half was provided by the city and half by relatives of the victims.

Moen said the Yoo case is one of the most brutal unsolved murder cases under investigation by the LAPD. “If someone did in fact witness these murders, we are asking that person to please come forward and help us bring the killer of this young family to justice.”