Manassas, Va. ? The death toll from the Washington-area sniper rose to seven Thursday as authorities said ballistics evidence had linked the killer to a man gunned down at a Virginia gas station.

Dean Meyers, 53, of Gaithersburg, Md., was felled by a single shot Wednesday night, moments after filling his car’s tank. Six other people have been killed and two have been wounded since the attacks began Oct. 2.

Prince William County Police Chief Charlie Deane said the results of an autopsy on Meyers and ballistic evidence had linked the cases. He pleaded for the killer to give up: “There’s enough damage been done.”

Police earlier said they were searching for a white minivan seen leaving the gas station in this bedroom community, but Deane said the van’s occupants had a reasonable explanation of their actions. He refused to say whether there were surveillance cameras at the station but said some cameras were in the area.

“It’s a difficult case, but we are developing more information as the minutes go by,” Deane said.

Manassas is about 35 miles southwest of the Maryland suburbs where most of the attacks happened. The shooting is the second in Virginia: A woman was wounded by the sniper Oct. 4 in Fredericksburg, 30 miles south of here.

Police in yellow slickers walked shoulder to shoulder through a drizzling rain, looking for evidence near the gas station. Deane did not say whether they found anything but said there had been no communication from the killer.

Investigators say the sniper, or snipers, fired from a distance with a high-powered hunting or military-style rifle. Like Meyers, all the victims were felled by a single bullet.