Larry Looney, who lived upstairs from Asa Coon in a duplex, said the two were lifting weights Tuesday when the boy told him about Monday's fight with another student and his three-day suspension.
"He really didn't want to talk about it," Looney said. "He said he really didn't do anything to start it. He said the teachers wouldn't listen to his side of the story.
"I just can't believe he would do anything like that."
Coon shot two teachers and two students Wednesday at SuccessTech Academy then committed suicide. All the shooting victims survived. One teacher remained hospitalized Friday in good condition.
Schools CEO Eugene Sanders said Friday that the school district would place metal detectors and security guards in all schools in response to the shooting spree. Metal detectors had been used intermittently at SuccessTech, and none were operating Wednesday.
Looney, 48, said his nephew was bullied and picked on his entire life and was thrilled to be accepted into SuccessTech, viewing it as his only chance to escape the daily beatings he took. Coon told him recently that he was having problems with some students at SuccessTech, an alternative high school in the Cleveland district that stresses technology and entrepreneurship for high-achieving students.
Looney wondered whether his nephew grew despondent that things weren't working out at the school.
"He really had high hopes because he knew ... this was his best chance, this was the safest type of environment," Looney said.
Students have said Coon recently threatened to blow up the school, but they did not take his threats seriously. Students said teachers knew about the threats but did nothing.
Looney never heard Coon make any threats against the school and never saw any warning signs. He said his nephew was an angry child, which Looney attributed to the bullying he received.
"When he was younger, he used to deal with his problems by tearing up his room," he said.
A few years ago, Coon talked about suicide and received counseling, which seemed to help. "After a while, he got to where he didn't feel like that anymore," Looney said.
He got good grades the previous two school years, received the required recommendations from school personnel and was accepted at SuccessTech for his freshman year.
"He wanted to go to a school where he didn't get bullied. Where he could learn," Looney said. "He liked to have sophisticated conversations with people. He was way beyond his years."
As a teen who read "War and Peace" and had opinions on global warming and world issues, he was different, and that's why he was picked on, Looney said.
He routinely got roughed up after school, coming home with scratches and bruises. Looney witnessed some of the beatings as his nephew walked down the street.