Angela Hayden, whose 16-year-old daughter attends Taft High School, said the assailant allegedly threatened to kill her daughter and other students last year while they were on a school bus during a field trip to Universal Studios.
"He was telling everyone that he had a list of people who messed with him over the years and that he was going to kill them," Hayden told The Times. She said the youth allegedly said his brother would be the first victim.
She said her daughter complained to a vice principal about the incident and that the teenager was expelled for several days. After the youth returned, Hayden said, she called the principal to find out why he was not permanently barred from campus. The principal declined to discuss the punishment, citing privacy concerns, according to Hayden.
"Everybody knew about this kid," Hayden said.
A neighbor who knew the suspect told the Associated Press that he was often teased because he was "a short guy" and "small."
Police declined to comment on those assertions Thursday, saying that they were still investigating.
Times staff writers Nicole Santa Cruz and Robert Lopez contributed to this report.