An autopsy to determine when and how Mollie died is planned for Wednesday.
Tuesday morning her body was found, 12 miles from where she went missing July 18th.
Mollie’s body was found buried under corn stalks.
The man accused of killing her, 24-year-old Cristhian Bahena Rivera was arrested on first-degree murder charges.
He is being accused of following Mollie, then kidnapping her and killing her.
How she died, is still not known.
At one point he tells us that Mollie grabbed ahold of her phone and said you need to leave me alone, i’m going to call the police, and then she took off running, he in turn chased her down, and then he tells us, that at some point in time he blacks out, and then he comes to near an intersection where we believe he then placed Mollie,” said Rick Rahn, special agent in charge, Iowa Division of Criminal Investigation.
Rivera, who is undocumented has a bail set at $1 million.
If convicted he could get life in prison without parole.
He will make his first court appearance today.
Earlier this month Mollie’s father told CBS News, their daughter had so much to look forward to.
“She couldn’t have been any happier, this was the summer of a lifetime. she was the best man at my wedding. she’s had an incredible summer, she was as happy as i’d ever seen her,” said Mollie’s father Rob Tibbetts, who lives in Fresno.
Mollie would have started her Junior year at the University of Iowa this week.