If you commit a crime and have a gun in your possession and someone dies during your commission of the crime, it should be prima facie evidence of Murder One. This would be regardless of whether or not you even displayed the weapon -- the death could be due to a heart attack or slipping on a wet floor to open the safe. Take a gun with you to a crime and you'd better be ready to do the time...or more.
And this would include replica firearms, toy guns, and even putting your finger in your coat pocket and pretending you had a gun.