The NYPD has dusted off a ten-year-old training video meant to teach officers how to avoid friendly fire, and has been showing it to all cops at roll call in the wake of last week's fatal cop-on-cop shooting in Harlem. The video features testimonials from plainclothes cops, sharing common sense advice for uniformed cops, such as not making assumptions about individuals based on ethnicity or attire. There are also instructions for undercover officers on how to respond when "professionally challenged" by a uniformed officer—first and foremost being stopping when someone yells, "Police! Don't Move!" and not "reflexively spinning."

An investigation is being conducted to try and determine whether deceased officer Omar Edwards followed that protocol before Officer Andrew Dunton fired six rounds at him (three hit Edwards). But there's now speculation that Edwards wasn't wearing a holster, as department regulations require (regardless of whether a cop is on- or off-duty) and that's why he was carrying his gun while chasing a man suspected of breaking into his car. A police source tells the Post, "He couldn't run while it was tucked into his pants... If he just had tucked it into his waistband, it definitely would have fallen out." And another source suggests that had Dunton seen a holster, he would have paused before firing, because "if you see the holster, you think, 'Cop.'"

The NY Times also looks at the training cops undergo—while scenarios involving people in civilian clothing who claim to be cops are part of drills, it's much different in real life: "Officers are charged up with adrenaline and stress. Hearing can be impaired. There are often civilians around, maybe crowds, or people hanging out of windows."