Last 2 Youths Convicted in Murder of Student : Courts: Stuart A. Tay was killed after teen-agers in plot to steal computer equipment feared he would betray them. Three others have already been sentenced.

Two Orange County teen-agers were found guilty Friday of first-degree murder in the 1992 New Year’s Eve killing of a 17-year-old honors student who was bludgeoned and buried in a back-yard grave in a case that gained nationwide attention as a troubling portrait of youth violence.

Kirn Kim, 18, and Abraham Acosta, 17, were the last of five youths convicted in the killing of Stuart A. Tay, a high school student from Orange who aspired to be a doctor like his father.

Kim acted as lookout while the others lured Tay to the back yard of Acosta’s Buena Park home. Acosta leveled the first of many blows to Tay’s body with a baseball bat.

The five teen-agers, most of them college-bound students at Sunny Hills High School in Fullerton, wanted Tay dead because they believed he was about to double-cross them in a planned theft of computer equipment.

Jurors said Friday that the case left them emotionally drained, and they expressed concern for the families of Tay and the five assailants who were caught up in the tragedy.

“It was a very difficult case for all of us,” jury forewoman Wilma Johnson said. “Our sympathies and hearts go out to all the members of all the families on both sides.”

“There were a lot of lives hurt,” said juror Jennifer Baker, who wept as the verdicts were read.

Kim closed his eyes tight and blinked several times as the jury announced the guilty verdict that could send him to prison for 25 years to life.

Acosta sat quietly at the defense table until Orange County Superior Court Judge Kathleen E. O’Leary began discussing sentencing. That’s when Acosta broke down, sobbing loudly as defense attorney Denise Gragg put a comforting arm around his shoulder. The judge ordered the courtroom cleared of spectators, but Acosta’s cries could still be heard in the hallway.

In addition to convicting both youths of first-degree murder, jurors found Acosta guilty of ambushing his victim--a special circumstance finding that means he faces the prospect of life in prison without the possibility of parole. But they rejected a second special circumstance charge that the killing had been for financial gain because he took $100 from Tay’s wallet.

Jurors also acquitted Kim of the special circumstance allegation that he ambushed his victim.

The prosecution said Kim and Acosta joined in plotting the killing, joining a dress rehearsal with their friends, helping dig the grave in advance and agreeing to dump the victim’s car in Compton to make the killing look like a carjacking.

Tay, a student at Foothill High School in Santa Ana, was beaten in Acosta’s garage with bats and a sledgehammer. When he did not die immediately, the youths forced him to drink rubbing alcohol and taped his nose and mouth shut before he was buried in a shallow grave that had been dug 24 hours earlier.

Linda Tay, the victim’s mother, said outside of court Friday that she is not fully satisfied by the verdicts. She said she could not understand why jurors did not conclude that Kim was guilty of lying in wait for the victim or why Acosta was not convicted of killing for financial gain.

“We all know he did dig the grave the day before,” Linda Tay said of Kim. “Certainly, it was well planned ahead of time.”

The sophisticated murder scheme and the sheer senselessness of the killing grabbed headlines from the start. But the case also shocked Orange County because the assailants and the victim were such unlikely suspects.

Most of them did well in school. The teen-agers spent their time cruising fast-food restaurants, doing homework and playing computer games.

The ringleader was Robert Chan, 19, of Fullerton, a onetime candidate for valedictorian, who was convicted in a separate trial in May.

Tay was a high-achieving honors student. But he also had another side, one that was intrigued with crime and gangs and liked to brag about involvement in spy networks and underworld activities. The talk was designed to impress those around him; there was no evidence that Tay was involved in criminal conduct.

Tay assumed an alias and said he was much older when he sought out Chan. The two hatched a plan to rob an Anaheim computer parts dealer and recruited the four remaining teen-agers to carry out the scheme, the prosecutor said.

When Chan discovered Tay was lying about his age and name, Chan decided to kill him.

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The key prosecution witness was Charles Choe, 18, of Fullerton, who pleaded guilty to first-degree murder for his role in the attack. In return for his testimony against his former co-defendants, Choe was prosecuted as a juvenile. The other teens were prosecuted as adults.

Deputy Dist. Atty. Lewis R. Rosenblum told jurors the five teens were all fully involved with planning and carrying out the murder scheme. But defense attorneys for Kim and Acosta had argued to jurors that Chan duped their clients into participating in the murder.

Deputy Public Defender Gragg presented evidence that Acosta is a mentally disabled youth who was easily led to believe that he was to strike Tay as part of a prank to scare the victim. The blow did little more than anger Tay, who was then knocked unconscious when Chan took over the beating.

Defense attorney Allan H. Stokke told jurors that Kim also was unaware a murder was occurring.

Acosta’s mother avoided reporters after Friday’s hearing. Sook Kim, Kirn Kim’s mother, told reporters that she and her son pray daily for Stuart Tay and his family, but said Robert Chan is to blame.

“He is a victim of Robert Chan,” she said of her son. “The only thing different is he is alive. We will be praying for Stuart Tay and (his) family for the rest of our lives.”