The mastermind of the 2002 sniper attacks that killed 10 in the Washington, D.C., region has been executed. A prison spokesman says John Allen Muhammad died by injection at 9:11 p.m. Tuesday at Greensville Correctional Center.

Muhammad was executed for killing Dean Harold Meyers at a gas station during the spree that terrorized Maryland, Virginia and Washington, D.C., over a three-week period. His teenage accomplice, Lee Boyd Malvo, was sentenced to life in prison.

Prison spokesman Larry Traylor says Muhammad had no final words. He says he didn't hear him utter a word the entire time.