Phoenix police said the school was not under an active threat, but that one of the two people stabbed had "life-threatening injuries."

Horne added that Maryvale has safety plans in place and a school safety officer (SSO) on campus during school hours. The difference between an SSO and a school resource officer (SRO) is that SROs are on school campuses full-time while SSOs are there one day a week, Horne said.