> this doesn't change what store security must do. There is no _must_ here. The police _must_ deter and punish crime. A private entity _may_ hire security if t

> this doesn't change what store security must do. There is no _must_ here. The police _must_ deter and punish crime. A private entity _may_ hire security if they find the police to be ineffective at stopping certain crimes. If walmart was robed while the security guard was off duty, it is still the police's job to investigate and arrest the criminal.