Heavily armed assailants killed a state police chief and an officer and wounded two more officers Tuesday in a brazen midmorning ambush in this violent border city, authorities said. Tamaulipas Preventive Police Chief Victor Berrones and officer Norberto Vazquez were killed and officers Jose Plata and Juan Sanchez were wounded when gunmen armed with assault rifles attacked their patrol car on the outskirts of the city, according to a police statement. Full Story