CCTV footage from the February 15th mass shooting released Wednesday shows the moment Gary Martin, 45, prepares to ambush law enforcement officials after being told he was being fired from his job of 15 years.

The clip, posted by police, shows four camera angles from Henry Pratt Co. in Aurora, Illinois, right after Martin pulled out his gun and began shooting at his industrial valve manufacturer workplace.

A new surveillance video shows Chicago police officers push and drag a student down a set of stairs in February at Marshall High School on the West Side before punching her and shocking her with a stun gun multiple times.

The video, obtained by the Chicago Sun-Times, appears to contradict the officers’ statements that the student initiated the violent encounter after the incident to justify their use of force — again raising questions of the oversight, training and stationing of police officers in Chicago Public Schools.