An employee at a store adjacent to the gas station where Jessica Heeringa worked the late shift said he noticed a man in a minivan talking to the missing Michigan mother, but didn't think much of the interaction until he learned she had been abducted.
"It just seemed to me that this was just another guy hitting on her, or whatever, because she was an attractive girl," Christian VanAntwerpen said of the Friday night incident.
"It was just an afterthought I almost didn't think about mentioning," he said. "[But] I thought it was my responsibility to say something about it."
READ MORE: Jessica Heeringa: Police Say It's Possible Missing Gas Station Attendant Knew Her Abductor
VanAntwerpen said he watched a man in a silver minivan approach Heeringa when she was at a gas pump, preparing to close the Norton Shores, Mich., Exxon station where she had been working alone on the late shift.
"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 said.
"It was just bizarre that he seemed to be actively looking for her, like he knew her and then had this attitude that he wanted to have a conversation with her and then conduct business, and that is what seemed really out of place to me," he said.
Police Tuesday released a composite sketch of the minivan driver, a person of interest described as a white male, 6-feet tall with a medium to heavy build. Police said he was last seen wearing a bright red or orange sweatshirt.
Surveillance video was also released of a minivan, similar to the one VanAntwerpen described, traveling northbound, away from the gas station around the time police believe Heeringa was abducted.
Police have also released the 911 call from a concerned customer who alerted authorities around 11:15 p.m. Friday after he found the gas station eerily empty.
"There's nobody here," the caller said. "There's a car here. There's another car out in front, but it's very suspicious why there's nobody here."
The man told the dispatcher he tried yelling and walked around the building, but he saw no signs of an employee.
Police said Heeringa's last transaction took place at 10:55 p.m., leaving a small window of time between when she was last known to be in the store and when she was reported missing.
"There is no sign of a struggle in the store, so it's possible she knew who the person was as a customer or as an acquaintance," Norton Shores Police Chief Daniel Shaw told said.
Heeringa's purse and keys were found inside the store, he said, and robbery didn't appear to be a motive because the store's cash drawer was left untouched.
Investigators have interviewed and cleared several people of interest, Shaw said, including Heeringa's fiance, with whom she has a 3-year-old son.
Hundreds of people gathered Tuesday night in a field across from the Exxon station to hold a candlelight vigil for Heeringa. Among those gathered was the missing woman's sister, Samantha Heeringa.
"It's very frustrating, you know. I want my sister back," she said. "But I have hope that she'll be found soon ... Everybody's a wreck and will be until she's found."