Actually, though, I think we need at least three additional evolutions to really make that a Dicken Drill:
1) Standing still, drawing from concealment, as shown in the video.
2) Same par time, but at the beep move off the "X" at least 3 feet while drawing.
3) Set par time to 12 seconds; for the third evolution run at least 30 yards total (can be up and back or in a circle) immediately before activating the shot clock; at the beep move off the "X" at least 3 feet while drawing.
4) Set par time to 14 seconds; for the last evolution run at least 30 yards total (can be up and back or in a circle) immediately before activating the shot clock; at the beep move off the "X" at least 3 feet while drawing; after 5 rounds move at least 3 feet to a different lateral position and complete remaining 5 shots.
The running is a poor-man's simulation of physiological fight-or-flight stress response. Your heart rate won't be a casual 68 beats per minute when confronting and active shooter. Could always include simulated cover and require movement to and utilization of that for the last 5 rounds in evolution #4.