Kings County Sheriff's deputies say the suspect was upset after a 13-year-old boy stole a bag of chips from her. Investigators say at that point, the girl took out a knife and stabbed the victim in the back.
Deputies say she claims she was only trying to poke him. The victim's injury was so severe he had to be transported to a hospital in Fresno.
Kings County Assistant Sheriff Dave Putnam said, "It was a folding knife that had a blade of about 3.5 inches long that can be concealed."
Superintendent Steve Bogan said, "I just want to make sure parents know we have a safe school and all schools are generally safe we have isolated incidents we have to diffuse from time to time."
School officials say teachers talked to students Thursday, about resolving conflicts peacefully.
The student was arrested for assault with a deadly weapon and will likely be expelled from school.