CONCORD, N.H. — Authorities are seeking to identify and speak with the owner or driver of a vehicle that was parked near a Concord trailhead on the day a couple disappeared while going for a walk, and were found dead days later.

“We have no reason to believe that this vehicle is connected to a suspect in any way,” Geoffrey Ward, senior assistant attorney general, said at a news conference Thursday. “It’s just an individual or individuals we hope to identify who were in the area that day.”

Stephen Reid, 67, and Djeswende Reid, 66, left their apartment on April 18 and went for a walk toward some trails. Family and friends did not see or hear from them after that, authorities said.

Their bodies were discovered the night of April 21 in the area of Broken Ground Trails, near the Marsh Loop Trail. They died of multiple gunshot wounds, authorities said.

The vehicle was parked at the Marsh Loop trailhead on April 18. It is a dark green Toyota RAV4, with a model year between 2006-2012.

“Detectives are also looking to speak with any and all persons” who were on area trails on April 18, Ward said.

Last month, investigators released a sketch of a man they called a person of interest in the case.

A $33,500 reward for information is being offered.