Never hit them in the head. Go for the collar bone. Works better. They were called Kel Lights back in the old days when I was a happy policeman.
Last complaint I drew was a guy that claimed I pistol whipped him. My completely logical answer was:
"Chief, why would I hit him with a $250.00 revolver when I had a $17.00 flashlight?"
I was in court one day watching a guy up for concealed weapon. The judge asked, "why was it loaded?" The guy answered, "well, if it weren't loaded it'd be as useful as a round rock, now wouldn't it?" He got probation.