German soldiers tasked with mass executions of civilians using firearms during nazi rule where severely traumatized, spending entire work days simply executing men, women, and children with rifle shots at the brain stem.

This was one of the motivations behind the administrative decisions to use gas chambers for executions, a practice previously used and well documented from the Action T4 involuntary euthanasia program and its associated experiments.

It is easy for a government official to draft and sign a document ordering a genocide but it is a different matter for a human being to do such inhuman things and it takes a serious toll.