The video you posted of the "flame" shoe has been retouched. Sharpened and had saturation fixed. The clarity of the original video I found by a cop who posted it is different then the one you posted... My guess is the red is blood. Look at the wall there; low laying bullet holes that probably hit the lower leg or grazed the back of the leg.
Mike, 45, q, rsbn all work
During a lockdown? Yes, you lock yourselves in a classroom with the door locked and lights turned off. And stay hidden from all interior windows.