wrong from when he wasn't acting right after school. >> he was sad and said he wasn't hungry at all. >> reporter: the boy died just a few days after leaving the hospital. other parents and students at the school say he was the victim of a bully who has victimized children before. >>. >> translator: one day my son told me the bully stabbed him with a knife. i didn't believe him at first. one day i ran into the bully's mother and she dismissed my complaint. >> reporter: this boy says the alleged bully choked him once and frequently terrorizes other kids. some parents claim the bully had been suspended for several days after pulling down a classmate's pants. school officials decline comments citing privacy reasons. an investigator with the state's attorney's office confirmed to cnn they're investigating the boy's death as a case of bullying. this investigator says the alleged bully denied any involvement when he was interrogated in front of his