How did a knife get through new weapons detection system at Maryvale HS?

PHOENIX (AZFamily) — Just two weeks after Phoenix Union School District rolled out its weapons detection system, a student was arrested for allegedly stabbing to death a classmate on campus.

Maryvale High School was one of the district’s first schools that took part in a year-long pilot program to test it before it went live at all schools in the district. But how the system at Maryvale operated Tuesday morning is now under the microscope.

According to police, 16-year-old Chris Aguilar took a 4-inch pocket knife onto campus and stabbed his classmate, Michael Montoya II, to death .

“It’s very sad for all parties involved,” said Charles Burns, senior advisor for The North Group , a security and risk mitigation company.

Burns, who is not involved in the case but has overseen secu