Fairfax County police have discredited witness accounts of an olive-skinned gunman and a cream-colored van at the scene of Monday night’s 11th sniper shoot ing, leaving investigators with little information in their hunt for the killer.

At a news briefing outside Montgomery County, Md., police headquarters today, Fairfax police Chief J. Thomas Manger said details from one witness who claimed to see a man firing an AK–74 in the Home Depot parking garage were “not credible.”

He also said witnesses reports of a cream-colored Chevrolet Astro van—similar to a vehicle seen fleeing Friday’s fatal sniper shooting at the Four-Mile Fork Exxon in Spotsylvania County— are not reliable.

Manger said the task force is following up on leads from other witnesses at the scene.

“We continue to be confident this case will be solved,” he said. The sniper spree began Oct. 2 and 3 with six slayings in Montgomery County and Washington.

The gunman then wounded a woman outside the Spotsylvania Mall Oct. 4 and a 13-year-old boy on his way to school in Bowie, Md., Oct. 7.

Next came fatal shootings at a Manassas gas station Oct. 9 and at a Spotsylvania station Oct. 11. The latest shooting occurred Monday outside a Home Depot store in the Seven Corners shopping center in Falls Church.

Police say they are still interest ed in a white box truck and white vans described by witnesses at other shootings, but don’t want the public to fixate on those type of vehicles because the sniper may be driving something else.

Montgomery police Chief Charles Moose said task force members are not discouraged, but they are now “getting back to the basics.”

“The message we’re trying to say is please keep an open mind,” Moose said.