FBI joins search for Iowa college student Mollie Tibbetts, who went missing one week ago

The FBI has joined the investigation into the disappearance of Iowa college student Mollie Tibbetts, who has now been missing for a week.

Iowa Division of Criminal Investigation spokesman Mitch Mortvedt said Tuesday that the FBI and state agents are taking over with volunteer searches called off.

"We're still asking for the public's help," Mortvedt said. "We'd like to get any information we can. The more eyes and ears we have, the better."

Mollie's boyfriend Dalton Jack tells KCRG that he received a Snapchat from her at about 10 p.m. on July 18 when she was dogsitting for him. She did not show up for work the following day.

Relatives believe earlier reports that Mollie vanished while jogging are not correct.

"I read somewhere that she was running in a cornfield. That's obviously not true," aunt Kim Calderwood told KCRG. “The run happened and then she was at the house as far as we know. I don't think she would've run in the dark."

Investigators are "leaning more and more toward something happening to her against her will," according to Mortvedt.

Authorities are focusing on areas that Tibbetts has known to have gone to in the past. The FBI are hoping computer forensics will help narrow where she might be.

"This could shake out a bunch of different ways," Mortvedt said. "We are hoping and praying for the best outcome."

Dozens of volunteers had been searching for the 20-year-old University of Iowa student, but had been hindered by the farm ground.

"We're racking our brains, thinking what can we think of to tell the investigators," Calderwood told the Des Moines Register. "It's the worst thing to want to fix something you can't fix."

Tibbetts was born in California but moved to Iowa when she was in fourth grade, according to KCRG.

"You've seen her pictures. She's obviously a physically beautiful girl but she's more beautiful on the inside," Calderwood tells the station.

With News Wire Services