Theory I have but can't prove is that a huge number of accidental gun deaths and suicides are murders that the cops are just too lazy to investigate https://people.com/human-interest/dog-shoots-kills-owner-freak-hunting-accident-kansas/
Dog Shoots and Kills His Owner, 32, in Freak Hunting Accident, Kansas Authorities Say

Officials in Kansas say a man has died after he was shot by his dog in a freak hunting accident

Peoplemag
Maybe in this case there's some really compelling evidence that the dog indeed somehow fired a shot and killed this guy. Feels extraordinarily improbable compared to the "another human being shot him then left" hypothetical though!

@mtsw people can be dumb with guns, but “put a loaded rifle in the cab with the safety off” strikes me as improbable. If nothing else, rifles are big and unwieldy. Having one point *at* the driver seems just implausible.

Most of the hunters I know would either use a case (good hunting rifles aren’t cheap), or would lay it horizontally, where a negligent discharge would strike the door.

Quick, someone check if he owed a cop money or something.

@mtsw Here's the original story:

https://www.kake.com/story/48213408/sheriff-hunter-dies-after-dog-steps-on-rifle-in-backseat-of-pickup-truck

Unless you take the sherriff's word for it, there's simply not enough information here to accept this very odd story at face value.

Sheriff: Kansas hunter dies after dog steps on rifle in backseat of pickup truck

The Sumner County Sheriff's Office says a man died over the weekend after his dog stepped on a rifle, causing the firearm to discharge. 

@mtsw Dark thought, but very plausible.
@mtsw unless the man was laying down on a front bench seat I don't see how the trajectory of the bullet is a life threatening injury. If it's how they describe this would be a shot in the ass. Suss. But I'm no cop.

@mtsw
TV Detective: The killer was extremely careful and left almost no physical evidence. But they made one crucial mistake, and that has been the key to cracking this entire case...

Real-life Detective: I don't know, maybe the dog killed him.