AMARILLO, Texas -- Police say an armed pizza restaurant employee shot and killed one of two suspects who were robbing an Amarillo pizzeria.Police say 29-year-old Ruben Rios and 36-year-old Clayton Morgan entered La Bella Pizza to rob it late Tuesday night.According to police, Morgan was armed with a BB gun made to look like a real weapon. Witnesses say he used the gun to make demands of store employees. One of those employees, a licensed firearm carrier, reportedly fired his weapon at Morgan after being threatened.Morgan was hit and later died at a hospital.Rios, the other suspect, has been charged with murder, under Texas law that allows a person to be charged with murder if they take part in a crime in which someone was killed.