You can say 'stop' or 'alto' or use any other word you think will work but I've found that a large bore muzzle pointed at someone's head is pretty much the universal language.
Clint SmithIf you're not shootin', you should be loadin'. If you're not loadin, you should be movin', if you're not movin', someone's gonna cut your head off and put it on a stick.
Clint Smith