Miguel at GFZ likes to say "If your cause is just, why do you have to lie?"

In this case it's "Why do you have to fake a crime?"

This bastard teacher planted a 9mm cartridge in a stairwell, then acted like he found it and called the cops, also causing a lockdown of the school.  He's on video, but pled not guilty:
Mr. Purcell’s lawyer for the arraignment, Leah J. Metro, said her client denied any involvement with the bullet that was found. Ms. Metro said Mr. Purcell has been an educator about 30 years, including about a year with the Southbridge district which is managed by the state because of chronic underperformance.

The teacher, according to authorities, admitted he was trying to bring attention to concerns about school safety. The teacher told authorities it needs more security, specifically metal detectors in the facility, which is a combined building for middle and high school students.
Take note of that 'managed because of chronic underperformance' bit; with teachers like this...