NORTON SHORES, Mich. (WZZM) -- A customer at the Exxon gas station says he overheard a man in a van talking to Jessica Heeringa before she was allegedly abducted.

Christian VanAntwerpen was buying gas about three hours before Heeringa was reported missing. He works at a store within sight of the station and told police just as he was leaving Exxon Friday night, a van pulled into the parking lot.

VanAntwerpen says he overheard the man in the van talking lightheartedly with Heeringa about being in the parking lot and not inside the store behind the cash register.

"Kind of joking almost; I think it struck me as weird because the guy did not go into the building. He wanted to wait until she was in sight and start having this conversation with her," VanAntwerpen told WZZM 13.

In an interview with ABC News, VanAntwerpen said the man seemed to flirt with the 25-year-old mother. "He was just like, 'Hey, what are you doing over here? Aren't you supposed to be inside?' Just kind of being real flirty, weird about it."

VanAntwerpen did not see the man's face, but he says he does remember the sound of his voice.

Norton Shores Police released asketch of the minivan driver Tuesday. The person of interest is described as a white male, 6-feet tall with a medium to heavy build. He was last seen wearing a bright red or orange sweatshirt.

Surveillance videos from anearby laundromat and bar show a minivan, similar to the one VanAntwerpen described, traveling northbound on Grand Haven Road around the time police believe Heeringa was abducted.