(CNN) -- -- Washington-area sniper John Allen Muhammad, 48, was executed Tuesday by lethal injection, a Virginia prisons spokesman said.
Virginia Gov. Tim Kaine denied a last-minute clemency request Tuesday for Muhammad, the mastermind behind the Washington-area sniper attacks of 2002 that terrorized the nation's capital.
During three weeks in October 2002, Muhammad and accomplice Lee Boyd Malvo, then 17, killed 10 people and wounded three, while taunting police with written messages and phoned-in threats and demands.