weapon: a thing designed or used for inflicting bodily harm or physical damage
if person can use phone book to injures or kills other person then it is weapon.
gun is merely tools person used to kill. remove guns will not change if person has desire to kill other person. It is act as catalysis in reaction if you think this way. (make it more easier for person to achieve goal)
my english is bad. however, It don't make up different on your ignorance.