WASHINGTON — Montgomery County police said Monday they need help locating a driver who may have witnessed a woman being fatally stuck by a van as she crossed a street in the White Oak neighborhood of Silver Spring earlier this month.

Elaine Rowena Allen, 71, was killed Nov. 9 after she was struck by a white 2010 Ford E250 van on Columbia Pike/Route 29 at Hillwood Drive around 6:40 p.m.

Police said the driver of a gray- or silver-colored sedan that was traveling southbound on Columbia Pike near Hillwood Drive at around 6:30 p.m. that night may have witnessed the collision and are asking the driver to contact the Collision Reconstruction Unit at 240-773-6620.

Police have identified the driver of the van as Carter L. Cockrell, a 75-year-old D.C. man. Cockrell, who was traveling south on Columbia Pike when he struck Allen, stayed at the scene of the crash, police said.

Detectives said they believed the gray or silver sedan was traveling in front of Cockrell’s van on Columbia Pike.

Police said they are still investigating the circumstances of the collision, including in which direction Allen was traveling and whether she was struck by other vehicles.

Anyone with information about the crash is asked to contact the Collision Reconstruction Unit at 240-773-6620 or the police nonemergency number at 301-279-8000.