Twelve Muslims have attempted to kidnap the daughter of one of the Danish cartoonists.
Update: See comments for the actual, milder story.
If a person were armed and nearby, and absolutely certain what was happening – say, if the person were the girl’s father and had yesterday been threatened with her kidnapping – it would be just if he shot all twelve on the spot. Yes. Yes it would.
Before you leap to the conclusion that I am advocating vigilanteism, read on. Societies entrust certain members with the administration of justice, according to common rules. They do so because experience teaches that trained persons acting according to rules will get justice wrong far less often than individuals acting on their own. Having an enforcement arm turns out to be wiser, because there is less jumping to conclusion, less emotional bias, less disproportionate response, than every-man-for-himself.
But the kidnapping of a child in the context of death threats to the parent is incompatible with attempts of human beings to live in a society together. It is so debased, so antithetical to human interaction, that the summary execution is not unjust. The perpetrators’ legal rights might have been violated in our hypothetical. Their moral rights would not have been violated.
(A policeman in this position has a different equation. His job is not only to prevent the crime, but to represent society’s overall interest in order and rule of law. The policeman must use the minimum force necessary to prevent the crime and bring the others into custody. The policeman would be committing an injustice if he shot more of them than was strictly necessary. But he would not be committing an injustice against those he shot – we have already established that all twelve can be reasonably expected to pose a lethal danger to a little girl. The officer would be committing an injustice against society, which has a right to expect that the accusation against its members be examined and verified before the state takes any action.)
Our proposed bystander might decide that it is wiser not to shoot everyone. He might hope that some of them might know useful information, the discovery of which would add to his daughter’s safety. He might believe he is surrounded by other armed men, who will shoot him and the daughter immediately. He may be a gentle sort who believes that even deeply evil men can be reasoned with. But these are questions of wisdom, not justice.
By the way, if 12 people attempted this crime, then 100 others know or can reasonably guess who they are. Bosses, family, neighbors – any of them might be aware that person X was not where he was expected to be at the time in question.