why are we so obsessed with murder?

We have been fascinated with death for some time now:
Fascination with death - Wikipedia

It could be quite a healthy thing:
Jay Doubleyou: optimism - our enemy
Jay Doubleyou: you can't get success and happiness through positive thinking

Here are some explanations of why we like 'true crime':
12 Reasons We Love True Crime, According to the Experts | Mental Floss
Why are people obsessed with true crime?—Hopes&Fears

And why we love murder fiction:
Why is Britain so Obsessed with Murder Mysteries?
Why Are We So Fascinated by Violence? | Psychology Today

Here's another suggestion why:
Social Conservatives’ Obsession with Crime | how to save the world

Finally, here's some context:
Jay Doubleyou: crime and punishment
Jay Doubleyou: crime statistics - and the perception of crime
Jay Doubleyou: a history of violence part two
Jay Doubleyou: a history of violence: another look at how violent we are
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