It was inevitable that the murder porn channel Investigation Discovery, an arm of the Discovery Network, would do a series on "bad teachers." The aim of this show is to propagandize the public against public school teachers because the profession is supposedly inundated with perverts and other sleazeballs who are protected by the no-good "unions."
Those teachers who commit criminal acts are always dealt with swiftly and are booted out of the profession by the states revoking their licenses. I seriously doubt there are more of those types than in other professions. The ones who are really bad but are not criminals have jobs for life and are typically administrators. They just generally aren't hitting on children or caught embezzling or whatever.
This show isn't alone in the anti-public education propaganda campaign. For example we have the CNN show "Chicagoland" which is nothing but an advertisement for corrupt mayor Rahm Emanuel and hails his destructive education policies. It has no place on a "news" program, but there it is.
You'd have thought Leni Riefenstahl had produced and directed the series.