The man who shot and killed a teenager in downtown Birmingham will not face charges. The Jefferson County District Attorney's office says the killing of 17-year old Isaiah Johnson is a case of justifiable homicide. Investigators say Johnson and a friend tried to rob the man during a gun deal. It happened on Second Avenue South near Railroad Park last week. Authorities are charging the teenager's friend with murder, saying the killing occurred during the commission of a crime. 17-year old Tavares Floyd is being held on $150-thousand dollars bond.