Rules, reasons and prosecutorial discretion unexercised

At base the legal system is merely a set of rules.

And those rules, all of them, are based on underlying policies.

Rules have reasons.

Rules for the sake of rules are nothing more than fetishes.

Now, having said that, I am not one who says every time we apply a rule we should consider afresh the policy underlying the rule. If we did that, or could do that, we won't need rules at all -- we could simply apply policy.

But sometimes we should ask if enforcing the rule promotes the policy the rule is designed to uphold and, if not, whether we should (this time) not apply the rule.

David Chen, the Chinatown shopkeeper, on trial for detaining a thief is an example.

Why do we not allow citizen's arrest broadly? Because it will be misused, misunderstood and lead to breached of the peace. Generally the police should detain suspects -- they are trained and paid to do that job.

But here it seems the police were not arresting (or even paying much mind to) thieves (and that's likely a resource issue so no blame follows). The effect was a lawless zone -- and a risk, a real risk, of breach of the peace.

In effect, even if Chen broke the "rule" - and I am most unsure he did - the enforcement of the rule here is contrary to its policy.

The sort of case the Crown ought not to prosecute.