But Mr. Bahena Rivera’s quiet demeanor sometimes stood out in jarring ways.
A neighbor said he did not always follow the local custom of acknowledging him when Mr. Bahena Rivera drove by in a Chevy Malibu.
And, more alarmingly, a woman said he made her uncomfortable with a romantic advance and repeated Facebook messages in the middle of the night.
“He would just stare. He wouldn’t really like talk,” said the woman, Brooke Bestell, 20, who had turned Mr. Bahena Rivera down when he asked her out on a date. “Something about him was off.”
Others found his behavior more troubling. Ms. Bestell, the acquaintance who declined a date with him, said he would not make conversation when she encountered him in person, but he would send repeated social media messages over a period of months.
“Just over and over, like every week or so, he would message me again,” Ms. Bestell said, including as recently as June 13 at 3 a.m.
After he was arrested, two of Ms. Bestell’s friends told her that he had also messaged them online over the years. “I don’t know how many other girls he probably was trying to talk to,” she said.
"I know Cristhian from my sister. She thought he was a nice, well-spoken person. They hung out a few times but nothing really happened romantically," Gibson said.
She started feeling uncomfortable around Rivera after he approached her in a manner similar to how he approached Tibbetts.
It was more flirty than sexual but my sister is very shy.She didn’t appreciate it."
"She told me that a little while ago he drove up to her while she was walking through Brooklyn," Gibson said. "He told her she was really pretty and things like that.
It was more flirty than sexual but my sister is very shy. She didn’t appreciate it."
"Even though she knew him a little she felt unsafe and didn't want to talk to him. In the end, she was really creeped out by his behavior. She had to keep telling him she wasn't interested."
Another man — who was only identified as Justin —
claimed that Rivera followed his fiancée in his car.
“I remember her calling me when she noticed how slow he was driving by in circles, turning around the block to keep up with her several times on her walk home,” he said.
“I vividly remember one day, it was around sunset or just after, my fiancée called because she was scared."
Justin said she was returning from getting groceries when Rivera drove past her at least six times.
"Now it’s really strange because of how long he’s been driving around like that. It makes you wonder if Mollie was his only victim.”
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