the more I understand about the body, the more uncomfortable I am in killing scenes. One cannot help it as a GM, World Builder, and Storyteller - getting some powerfully sticky details that just burn itself into your mind.
1) people just don't die "instantaneously" when hit in a vital part. As long as there is oxygen in their blood and atp in their muscles involuntary movement happens. Some part of them is still "alive". from the bowel movement of dying, to the enemy that holds the trigger down even after dying unleashing a spray of death to its own allies or at the PC involuntarily.
2) a lethal injury means the person is either in Numb or Painful agony until they die.
3) that burning is its own kind of torture
4) that oxygen starvation from drowning or waterboarding is also another kind of torturous pain.
4.1) the destruction of brain areas in oxygen starvation is a special kind of torture as parts of oneself cease to exist and can never be the same.
5) that consciousness has a relativistic time element - it can stretch out time or it can just shut off abruptly.
6) Characters with enough battle first aid will have extensive knowledge of injuries. Combat physicians will have knowledge of injuries and LONG term effects. Both calls for a sanity check.
7) My idea of mercy kill is an opiate overdose.
I stumbled on the reddit discussion about Chris Watts. I follow the morbid reality thread in reddit as part of my mindfulness reflections as well as my study of Horror after finishing GURPS Horror by kenneth hite (4e). The analysis of what constitutes a "Sanity Check" overlaps heavily with my Psychology, mindfulness, emotional intelligence, Cognitive-behavioral Therapy Studies. Note that Psychology and Behavioral studies overlap with Game Theory and Economic Studies if as a GM we want to simulate authentic behavior for players and analyze behavior we observe.
The reddit thread talks about some bits on the autopsy reports of the murders which if ever done to the NPCs the players kill, it would be interesting to get their reaction.