Hmmm . . . Joseph Smith murdered by a lynch mob - your kind of justice? Amazing. No wonder many of us saints keep our powder dry as well as our preparations for emergencies up to date.
Duh, old man...I said it was too bad Joseph Smith was murdered. I didn't say he deserved it.
Lynch mob is in YOUR history books - but not necessarily ALL history books. There are renditions of his murder that say Joseph Smith had a weapon (gun) inside the jail and fired at the mob. He was killed in the return fire.
In your history he was listening to Hyrum sing "A Poor Wayfaring Man"...when suddenly a frenzied mob opened fire on the jail. Jospeh Smith was struck with a ball during the attack - and fell from the second story of the jail.
Now tell me - why was a man sho was being fired upon standing at an open window??
Possible answer #1: To see the faces of the men that were going to kill him.
Possible and more probable answer #2: To return their fire.