canada
The bank robbery is prohibited by the Criminal Code. It would be an offence under s. 343.
Two conceivable defences might be self-defence or necessity.
Self-defence is only available to respond to force or threat of force. See s. 34. It does not apply in the circumstances.
The Criminal Code preserves the availability of common law defences (s. 8), and necessity is one of those.
Necessity requires:
- imminent danger or peril;
- no reasonable legal alternative to the course of action he or she undertook;
- the harm inflicted by the accused must be proportional to the harm avoided by the accused.
The standard of immenence and no reasonable legal alternative is very high. See Perka v. The Queen, [1984] 2 SCR 232:
In my opinion this restriction focuses directly on the “involuntariness” of the purportedly necessitous behaviour by providing a number of tests for determining whether the wrongful act was truly the only realistic reaction open to the actor or whether he was in fact making what in fairness could be called a choice. If he was making a choice, then the wrongful act cannot have been involuntary in the relevant sense.
The requirement that the situation be urgent and the peril be imminent, tests whether it was indeed unavoidable for the actor to act at all. In LaFave & Scott, Criminal Law (1972), at p. 388, one reads:
It is sometimes said that the defense of necessity does not apply except in an emergency—when the threatened harm is immediate, the threatened disaster imminent. Perhaps this is but a way of saying that, until the time comes when the threatened harm is immediate, there are generally options open to the defendant to avoid the harm, other than the option of disobeying the literal terms of the law—the rescue ship may appear, the storm may pass; and so the defendant must wait until that hope of survival disappears.
At a minimum the situation must be so emergent and the peril must be so pressing that normal human instincts cry out for action and make a counsel of patience unreasonable.
The requirement that compliance with the law be “demonstrably impossible” takes this assessment one step further. Given that the accused had to act, could he nevertheless realistically have acted to avoid the peril or prevent the harm, without breaking the law? Was there a legal way out? I think this is what Bracton means when he lists “necessity” as a defence, providing the wrongful act was not “avoidable”. The question to be asked is whether the agent had any real choice: could he have done otherwise? If there is a reasonable legal alternative to disobeying the law, then the decision to disobey becomes a voluntary one, impelled by some consideration beyond the dictates of “necessity” and human instincts.
The importance of this requirement that there be no reasonable legal alternative cannot be overstressed.
Whether the threat of leukemia is sufficiently immediate, and whether compliance with the law is demonstrably "impossible" are questions of fact that you can assess for yourself.