St. Petersburg police officers have added the Colt AR-15 rifle to their inventory to counter the expiration of the assault weapons ban and the appearance of more heavily armed criminals. ST. PETERSBURG - (AP) -- The expiration of the nation's ban on the sale of assault rifles and the appearance of more heavily armed criminals have pushed more than 100 St. Petersburg police officers to order assault rifles of their own for official duty. The first group of officers completed the required 16 hours of instruction for using Colt AR-15s in January. The semiautomatic weapons fire bullets that travel up...