 Authorities say that on Friday night, three officers stopped 13-year-old Nai Mui and another 13-year-old in connection with a string of nearby armed robberies. According to body camera footage released by police, an officer asked to pat Mui down, and that's when he ran. Officers chased him down the street and said they had seen a handgun in the boy's hand. Authorities later determined that it was a pellet gun.