According to the book of Mormon (musical not actual book) he was murdered. I trust my kevin price and you should too.
"Now comes the part of our story
That gets a little bit sad
On the way to the promised land
Mormons made people mad
Joseph was shot by an angry mob
And knew he'd soon be done"a direct quote from the song: All American Prophet
Joseph Smith was falsely accused of things and then the mob killed him. They shot him several times, and he fell out of a window. He did not do anything! He was innocent and had no reason to die. Therefore, he was murdered in cold blood, which was very unfair.