By MICHAEL BALSAMO, NOMAAN MERCHANT and COLLEEN LONG WASHINGTON (AP) — A Capitol Police officer was killed Friday after a man rammed a car into two officers at a barricade outside the U.S. Capitol and then emerged wielding a knife. It was the second line-of-duty death this year for a department still struggling to heal from the Jan. 6 insurrection. Video shows the driver of the crashed car emerging