Virginia ? John Allen Muhammad, the mastermind behind the sniper attacks that left 10 dead, was executed Tuesday as relatives of the victims watched, reliving the killing spree that terrorized the Washington, D.C., area for three weeks in October 2002.

The 48-year-old Muhammad looked calm and stoic, but was twitching and blinking, tapping his left foot as the injections began, defiant to the end, refusing to utter any final words. Victims’ families sat behind glass while watching, separated from the rest of the 27 witnesses, who were quiet, looking straight forward, intent on what was happening.

“He died very peacefully, much more than most of his victims,” said Prince William County prosecutor Paul Ebert, who witnessed Muhammad die by injection at 9:11 p.m. at Greensville Correctional Center, south of Richmond.

Muhammad was executed for killing Dean Harold Meyers, who was shot in the head at a Manassas gas station during the three-week spree across Maryland, Virginia and Washington, D.C.