Death squads, i.e. assassination teams, go back to World War II. I know because a dead family member was taken out of juvenile detention for gang-related crimes committed in a large city, back in the late 1930's in Canada - and then was mustered into one of these hit teams sent into Nazi-controlled France.

He didn't have to be 'mind-controlled', just coerced and threatened.

I don't know who the people were that his bunch killed - I'd like to think only Nazis or French traitors. But one is never sure, is one?

Funny, his name never showed up on any records of the Canadian Armed Forces, in any branch. He was never entitled to veterans benefits.

After the war, he worked for mobsters here and there across North America. He became a real nut job.