ADAMS COUNTY, Colo. (CBS4) - The body of 19-year-old Natalie Bollinger was was found in unincorporated Adams County last week.
How she died remains a mystery -- along with what happened during 24 hours she was missing.
"We don't have anybody who was either talking with her through social media or through text or in person or on the telephone. Those are the critical 26 hours for us," investigators said.
Family members reported the teen missing on Dec. 28.
She was last seen at her Broomfield apartment.
Her body was found following day on the property of McIntosh Dairy in Adams County.
A Facebook post Bollinger made just one week before her disappearance fueled a firestorm of speculation on social media.
The post was a public warning about a man she said had been stalking her for years -- Shawn Schwartz.
Bollinger claimed Schwartz drove across the county to see her, and "slept behind her work for weeks."
On Dec. 15, she filed a restraining order against Schwartz.
Investigators said they have talked to Schwartz but they aren't ready to call anyone a suspect.
Schwartz made his own posts about the accusations -- calling Bollinger a friend.
In September, he wrote to Bollinger saying he wanted to kill himself and for her to be there to watch.
The Adams County Sheriff's Office says the posts are part of their investigation but warned of the trouble social media can cause.
On his Facebook page, Schwartz talked about his time with investigators. He said he provided them his cellphone, computer and a DNA sample, and that he was let go.
Bollinger's family members in a statement say they are heartbroken and asked anyone with information to call the sheriff's office.
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