Murder Suspect Appeared to Be on Fast Track to Success : Crime: The alleged mastermind of the slaying of honors student Stuart A. Tay was an academic achiever. His classmates are bewildered.

Like others his age, Robert Chien-Nan Chan faced the usual highs and lows of life as a teen-ager. But unlike most, he rose above the crowd and was often considered among the best.

He traded his eighth-grade violin for cleats to join the football squad during his first two years at Fullerton’s Sunny Hills High School. Though a mediocre player, teammates say his hard work and determination earned him the respect of the stars on the team.

Academically, he excelled to the point of becoming a contender for class valedictorian. He was in a demanding honors program. And he was on the school’s Academic Decathlon team.

By all appearances, he was on the fast track to success.

Suddenly, however, Chan’s future is uncertain, thrown into a wild spin by his arrest--along with four other Sunny Hills students--in the gruesome New Year’s Eve murder of Foothill High School honors student Stuart A. Tay.

Is it possible that Chan could have masterminded the killing because he believed Tay crossed him while planning a theft of computer parts, as police now allege?

His classmates say it does not make sense.

“When you watch TV and read the news about someone normal and quiet, and suddenly that person went berserk . . . maybe Robert was one of those people,” said Royce Liao, a Sunny Hills High School senior. “But he is my friend. . . . I still believe he’s innocent.”

Orange police theorize that Chan and four other students--Charles Choe, 17; Kirn Young Kim, 16; Mun Bong Kang, 17, and Abraham Acosta, 16--participated in Tay’s killing because Chan felt deceived in a scheme to rob an Anaheim man of computer components.

Investigators say Tay was lured to Acosta’s house in Buena Park on New Year’s Eve on the pretense of selling him a Beretta handgun. But under a plan allegedly devised about two weeks in advance, Tay was beaten with baseball bats and a sledgehammer and then buried in a shallow grave in Acosta’s back yard.

Of the estimated 13 blows delivered to Tay’s head and stomach, police believe Chan struck the victim at least 10 times, according to court records. Investigators also allege that Chan arranged to pay Acosta for digging the grave, distributed the money found in Tay’s wallet to other accomplices and made plans to abandon Tay’s Nissan 300 ZX sports car in Compton, providing the driver with plastic gloves to avoid leaving fingerprints on the car.

Fullerton police now say Chan was one of the suspects last year in the beating of a teen-ager. The victim declined to press charges, but investigators believe Chan and others attacked the teen-ager for bad-mouthing the Wah Ching, a national Chinese gang centered mainly in Los Angeles and San Francisco that has been involved in crimes ranging from homicide to extortion. Chan had boasted to friends of ties to Wah Ching, said authorities and friends of Chan.

Chan and his attorney have declined requests for interviews, as have his parents.

As Chan’s classmates pore over newspaper accounts of the police case, they have trouble making the pieces of the puzzle fit. The Robert Chan they know is not a likely murder suspect.

One of the oddities, they say, is that Chan does not have a sophisticated knowledge of computers, unlike the murder victim and at least one other suspect.

Friends say Chan needed help learning to use a new top-of-the-line computer system that his father recently acquired. One friend gave Chan advice on how to install a computer game, and another explained the word-processing and other software programs.

“It just seemed like (Robert) didn’t know much about (the new computer). If he were trying to find out about computer parts, I would have known instantly because I know about computers myself,” Liao said.

Friends also say it would be out of character for the normally low-key Chan to order his accused conspirators step by step through the attack, as police contend.

And, friends wonder, why wouldn’t someone known for being meticulous in his work and in his dress have drawn up a more careful murder plan?

“Even if it was premeditated and he planned everything, he’s a smart guy,” said one friend, who spoke on the condition that he not be identified. “He would not make a plan like that and bury the guy in the back yard.”

The son of an engineer and a homemaker, the shy Taiwan native seemed to have a little trouble fitting in when he first arrived as a seventh-grader at Russell D. Parks Junior High School in Fullerton. His extracurricular activities were not extensive, but he played the violin for the school’s string band. From music, his interests moved to sports, and he joined the freshman and junior varsity football squads.

Former teammates remember that Chan left football to devote more time to his studies. Friends believe that it was during this time that Chan briefly courted Jennifer Lin--the girl who was dating Tay at the time of his death. She is the only girl that Chan is known to have dated, and his friends say she broke it off.

The Tays’ private detective initially speculated that Chan and Tay may have been in conflict over the girl, but police quickly dispelled that theory, and so do Chan’s friends.

One close friend who asked not to be identified said he spoke to Chan on New Year’s Eve and again the next afternoon--before and after the homicide. They spoke of unfinished class assignments and of what they had done during the holiday break. “He sounded perfectly normal,” he said.

And when students returned to campus the following Monday, no one detected anything unusual until a vice principal pulled Chan out of his fifth-period honors English class. “Later the vice principal came back and got his bag,” a classmate said, “and we knew he wasn’t coming back.”

Times staff writer Jodi Wilgoren contributed to this report.