JOEL - Joseph Smith did not murder anyone. His actions were clearly in self defense and in defense of his friends who were with him on the day he died. If you will check the dictionary the definition of murder is "The unlawful killing of one human by another, especially with premeditated malice." (American Heritage Dictionary)
What Joseph Smith did was not unlawful and it was not done with premeditated malice. Perhaps you are not aware of what happened the day he died. Please go to this page to read the story.
Reports of Joseph killing two men are contradicted by other reports that he only wonded them. According to an eyewitness testimony, one man was shot in the arm, another was shot in the face and the third was shot in the shoulder, but none of them died.
Joseph was not a murderer, but he was a martyr. He requires no forgiveness for what he did. On the contrary, he will be exalted in the highest kingdom of God in heaven for all He did during his life and for dying for what he believed in.

DEBBIE - When they came for Jesus, He told them they didn't take his life ....he gave it willingly and Jesus never tried to defend himself. If Joesph Smith is the holy prophet that you believe him to be, He would have never defended himself. Not Jesus nor any of his disciples defended themselves against the attacks they were subjected to unto death. I am sorry but I can not agree with you that even in self defense that he was a lamb led to slaughter. A lamb or a True Prophet would not have pulled out a gun to avenge or defend themselves.

JOEL - I know some people have a problem with calling Joseph Smith a "martyr", because of the fact that he did try to defend himself while being attacked. This depends on what your personal definition of a martyr is. Webster's definition of a martyr is:

1. A person who voluntarily suffers death as the penalty of witnessing to and refusing to renounce a religion.
2. A person who sacrifices something of great value and especially life itself for the sake of principle.

I do not know of anything in the job descripton for a true prophet, that prohibits him from defending himself from an enemy, who is violently attacking him.
If he were placed in a prison and told that he must renounce his religion or die, a true prophet would of course willingly choose death. But those who attacked Joseph Smith did not give him a choice. He also had to consider the lives of his friends who were with him. He did not want them to die. So when the mob attacked, his instincts of self preservation took over to do what he could to save himself and the lives of his friends.
By your definition of what a prophet would do, Elijah must also have been a false prophet, for he twice called down fire from heaven to destroy groups of 50 men sent by the king to arrest him (2 Kings 1:9-12). Elijah slew a hundred; Joseph Smith may or may not have slain two men. Moses also slew a man he caught harming another (Exodus 2:11-14), yet God chose him to be a prophet. Another biblical prophet, Elisha, angered because young people were taunting him because of his bald head, called she-bears out of the woods to devour them (2 Kings 2:23-24).
The defensive actions of Joseph Smith and his companions at the Carthage jail parallel what happened when chief priests came to arrest Jesus in the garden of Gethsemane. Peter drew a sword and smote off the ear of the high priest's servant (Matthew 26:51; Mark 14:47 Luke 22:50; John 18:10) with one of the two swords that Jesus had allowed the apostles to bring with them from the upper room (Luke 22:38). Jesus allowed them to bring the swords for defense and Peter, who was a disciple, used violence to defend Jesus. But he still remained as the chief apostle after this.
The apostle Paul resisted being put to death through Rome’s legal and judicial system, apparently taking advantage of every provision of Roman law that might bring an acquittal(Acts 22-28).
The stories about the deaths of most of the other apostles are all based on tradition and not supported by any existing records.
Prophets are not always perfect like Jesus was. Joseph Smith himself said,
"Although I was called of my Heavenly Father to lay the foundation of this great work and kingdom in this dispensation, and testify of His revealed will to scattered Israel, I am subject to like passions as other men, like the prophets of olden times" (History of the Church 5:516).
I only bring up these things so that Joseph Smith can be fairly judged.
Prophets and Apostles are human. Sometimes they do die as martyrs, but if they don't, they are no less a prophet.