AR vs 12ga vs 9mm Compare for Home Defense

Testing the most popular platforms for home defense in the USA, but with regular people instead of only those who shoot on a regular basis:

12 ga pump
AR-15 in 5.56 (12.5" Colt build)
9mm handgun (S&W Shield)

Settling the debate on best home defense firearm with a group test of shooters ranging from learning that day to seasoned soldiers to see what really handles best, is easiest to learn, and most importantly - gives results!