Prisoners generally don't have the jailers provide pistols for them. Dig around some more - Smith was expecting the Nauvoo Legion to come and bust him out and initially thought the mob was the legion come to the rescue.
True but irrelevant. Does not excuse the actions of a murderous mob. Or those of the jailers who conspired in the murder of the men in their charge.
To those who think this was not murder: It was most definitely homicide. So if it wasn’t murder, it should presumably be be considered justifiable under the law.
What justified it? The fact that the mob (and you) hate the guy so much?