General legal premise: no person owes a legal duty to another, absent some special relationship. As they teach in Torts 101, if a person sees another person drowning, realizes he can save them at no risk to himself, and instead decides just to watch, he may have breached a moral duty, but not a legal one. The same holds true (with much less basis) of a law enforcement agency and a victim of crime. Warren v. District of Columbia being a particularly stunning case.

BUT — if others choose to rescue the drowning person, the onlooker must not hinder them. Nor can the onlooker create the false impression that he is trying to rescue the person, because that might inhibit other people from trying to do it. The onlooker need not attempt a rescue himself, but if he does anything to reduce the chance that another might choose to do it, he becomes legally liable for the outcome.

I’d say that tackling and handcuffing people who were trying to go in meets that test. So would stopping the Border Patrol agents who were willing to charge in.

Hat tip to reader Jay Dee for this idea.