Should Hector Kill the Coffin-Maker?

More moral dilemmas courtesy of D&D.

My character, Hector, has been charged with the task of recovering a holy relic that belongs to, and protected, a local church. The relic had been stolen, and without it, the church is vulnerable to attacks by undead monsters. Hector has learned the identity of the thief, a coffin-maker named Henrik, and may now go confront him. But here's the dilemma: After recovering the stolen relic, Hector will likely have an opportunity to either kill the coffin-maker, or spare him. Hector has decided that he should have killed the ruffians. Now he must decide whether he will kill the coffin-maker.

On one hand, killing is usually wrong. When there is a peaceful solution, killing is almost always wrong. It is very likely that Hector will be able to reclaim the relic without killing the man who stole it.

However, if the coffin-maker is spared, what would prevent him from stealing the relic again? And there is the law of justice to consider. There must be some punishment or recompense.

Yet, this is not like the encounter with the ruffians on the road. This isn't the lawless wilderness. We're in a town. This town is certain to have laws and those whose job it is to enforce those laws. Certainly, this thief could be satisfactorilly penalized by the local law-enforcers.

But that requires the local law to be just, and one cannot always count on the law to be just.

Then, should Hector take the law into his own hands? Should he mete out his own form of justice? Probably not. Though, perhaps it depends on the coffin-maker's motives. If the coffin-maker's motives were evil and the corrupt legal system would let him go unpunished, perhaps Hector should mete out a more just punishment (though killing is probably still too much). However, if the coffin-maker's motives were good, perhaps no punishment is deserved at all.

As before, I wish I knew more about the situation, but fortunately, this time, Hector still has time to ask. Hector can learn about the thief's motives and the justice of the local legal system before making any permanent decisions.

Still, I suspect it will be a tough moral decision, but ultimately, I think it would probably be best to err on the side of mercy. Hector probably shouldn't kill the coffin-maker, and he probably won't, but it's interesting to think about these moral decisions and to speculate about the situations in which he actually should kill the coffin-maker, as unlikely as those situations might be. There is a line that divides those who should be killed and those who shouldn't, but I wonder where, exactly, that line is, and how Hector can determine whether or not the coffin-maker has crossed it.