A shooting rampage in Colorado Springs on Saturday left four people dead, including the assailant, who was gunned down after the authorities said the person fired at officers. The authorities in Colorado Springs said that gunfire was reported shortly after 8:30 a.m. in a largely residential area just east of downtown. When officers encountered the suspect, the person had moved just over a half-mile away to an intersection with fast-food restaurants, businesses and a high school campus. The suspect began shooting at the officers, several of whom returned fire. The authorities said the assailant’s motive was unclear.