LAS VEGAS (AP) — The Las Vegas public transportation system is investigating how it uses surveillance video and vehicle advertisements, a week after a fatal shooting and barricade situation on a public bus shut down the Strip hotel-casino district for hours. Angela Castro, spokeswoman for the Regional Transportation Commission of Southern Nevada, said in a statement Saturday that the agency is working with Las Vegas police to examine those issues from the March 25 incident. Police said Rolando Cardenas, 55, fatally shot one man and wounded another on the double-decker bus in front of the Cosmopolitan hotel-casino before barricading himself inside for more than four hours.