When Detectives Cause Deaths

One of the more disturbing motifs that floats through mysteries is the possibility that the detective's actions may lead directly to a death. 

In Unnatural Death: The Dawson Pedigree, Wimsey is so bothered by this possibility that he stops to talk to a priest. 

He and Charles Parker have begun investigating a death that no one suspects was a murder. The truly evil--though psychologically consistent--villain is paranoid about the chance of discovery and kills off witnesses, not to the actual murder but to the villain's motive. Wimsey fears--in some ways, correctly--that his investigation put the witnesses in the villain's crosshairs. 

The priest points out that the woman was killing off potential witnesses before Wimsey began the investigation. However, several years later, during the investigation associated with Gaudy Night, Wimsey brings up the issue again. When the female professors start criticizing his bourgeois crime-fighting hobby, he blandly replies, "Let me give you better weapons." He then asks the question, in sum, "Is the truth worth the fall-out?" 

Wimsey and the professors determine, "Yes." But Wimsey is well-aware of the reality of his actions, stating to Harriet, "The first thing a principle does is kill someone." 

Sayers herself doesn't come down entirely on Wimsey's side. During Wimsey's investigation, a female professor  admits to Harriet that another female professor would have done what she did--exposed the plagiarism of a scholarship candidate--but would also have taken steps to mitigate the ensuing disaster.

Agatha Christie came down on the "leave well enough alone unless it is your problem" side. She wrote the dark and rather terrifying novel--which got made into a movie with Donald Sutherland--Ordeal by Innocence, in which the investigation by an amateur detective who thinks he is the alibi for a wrongly accused man destroys the tentative status quo of a community. 

Agatha Christie believed that the purpose of an investigation was not to punish or protect the accused but to protect the innocent and society.

Cadfael in One Corpse Too Many makes a similar argument. The murdered man was thrown in among lawfully executed men. Some of those present argue, Why bother to investigate? 

Bother, Cadfael answers, Because that man isn't accounted for--we know why the others died but not why this one died. The social order demands a reckoning in order to remain stable.

In Elementary, Sherlock likewise refuses to allow a man to incriminate himself. To Kitty, he points out that there is no telling what greater problem or truth or villainy is at stake until the investigation is completed. 

Overall, I side with the detectives. But I confess, there are those stories where I think, about the detectives, "You know, maybe you should have decided to do something else that day." And left well-enough alone.