I suspect your prison guard friend was having you on.
You would be wrong. She was very serious. She doesn’t lie about stuff.
It also makes sense to some extent, if there is a civil war/violence, and a risk that Murders could be set free by those forces, and join them, then eliminate the risk.
Now I did not go into all the details about the criteria that would be required before the order was given by the Warden.
She was asked point blank in her first interview, if she understood that she might have to fire a weapon and kill an inmate.
Later training regarding the rest.