[Tammy8]

You are correct. They did kill a man in January, at one of the NV facilities.

https://www.thedrive.com/the-war-zone/26201/bizarre-chase-through-high-security-nevada-nuclear-test-site-ends-in-deadly-shooting

[fidelis]

It also happened a just a few years ago over at Luke AFB here in Arizona:

1 Dead After Air Force Base Guard Opens Fire at Stolen Car

"Use of Deadly Force Authorized" means "Use of Deadly Force Authorized." Period.