A Charleston man was fatally shot Tuesday evening in an exchange of gunfire, prompting a homicide investigation, police said.Jaiden Deamphis Weekes, 20, died after being taken to an area hospital from the scene of a shooting in the 1500 block of Lewis Street, according to a news release from the Charleston Police Department. The news release said Weekes was found in an alley suffering from multiple gunshot wounds. Investigators said about 10:42 p.m., Weekes drew a gun and began firing at a residence. An occupant returned fire, striking Weekes.Police said the case has been referred to the Kanawha County Prosecutors Office.