Students returned to Maryvale High School in Phoenix on Aug. 25, less than a week after 16-year-old Michael Montoya II was fatally stabbed during a classroom fight on Aug. 19. The Maricopa County medical examiner has ruled the death a homicide. Police say another 16-year-old student, Chris Aguilar, used a four-inch pocketknife in the attack, prompting an immediate lockdown and a shift to remote learning for the rest of the week. The Phoenix Union High School District said counselors and other resources are on site and that it is re-evaluating campus security. Although the district installed advanced weapons-detection systems across its campuses earlier this year, officials acknowledged the knife passed through undetected. The district has now increased the number of police officers on campus and is reviewing screening protocols. Tensions over safety escalated on Aug. 28 when an Arizona state lawmaker and her teenage daughter were escorted off the campus after they allegedly tried to carry a box cutter into the school to test the detection equipment. No injuries were reported, but the incident has added pressure on administrators to demonstrate that security upgrades can prevent further violence.