A shooting in Virginia has been linked to last week's sniper killings in Maryland and Washington, D.C., authorities said, as they continue to follow up on hundreds of leads in their search for the killer or killers. In Virginia, authorities said late Saturday that the bullet used in the shooting of a 43-year-old woman in a parking lot was fired from the same weapon used to kill four people in Maryland and Washington. ive people were shot and killed in Montgomery County during a 16-hour period from Wednesday night into Thursday morning. A sixth victim was shot dead Thursday night on a Washington street. The woman, who had been loading purchases from a Michaels craft store in suburban Fredericksburg, was struck by a bullet that pierced her lower back, exited her chest and lodged in her Toyota minivan. She was in stable condition at a Fairfax hospital.