The search for missing University of Iowa student Mollie Tibbetts has gained overwhelming national attention since her disappearance three weeks ago, along with a reward amount that surpasses most other missing persons cases. A National Center for Missing & Exploited Children spokesperson explained why cases such as Mollie’s tend to get more attention than other cases.

According to NCMEC spokesperson, Robert Lowery, cases such as Mollie’s, when someone vanishes without a trace and without any purpose or reason, are extremely rare.

“We always have a very small percentage like we’re seeing with Mollie, where they just simply disappear and for no investigative reason or for any purpose that we can determine, and these would make cases like Mollie’s the most difficult that anyone can face,” Lowery told KTVQ.

According to NCMEC, over 27,000 children were missing in 2017. Around 91 percent were considered endangered runaways, while 5 percent were family abductions, and 1 percent were non-family abductions. The remaining 3 percent were considered “critically missing” young adults between the ages of 18-20, while less than 1 percent were injured and lost children.

Mollie’s father, Rob Tibbetts, agreed with Lowery’s assessment.

“The situation with Mollie is so extraordinarily rare,” Tibbetts said. “You know as somebody put it, it’s the all-American girl who lives in a Norman Rockwell community, in love with the boy next door, vanishes into thin air and so ‘poof’ it doesn’t make sense.”

Those close to Mollie said there was no indication from her that she was unhappy or planning to leave on her own without telling anyone. Mollie’s mother, Laura Calderwood, said her daughter was getting ready to move into her own apartment and had recently ordered bed sheets for the new place.

“She took out a lease, she was ordering sheets and bedding from Target, you know i’ve told people that I’ve got the sheets and I’ve got the bedding but I don’t have the girl.”

The family, with the generous help of donors, is offering $300,000 for Mollie’s safe return.

Timeline of Mollie’s disappearance

July 16-17

• Mollie’s boyfriend saw her for the last time on July 16, before leaving town to work at a Dubuque construction site with his brother, around 100 miles away from Brooklyn.
• On July 17, Dalton and his brother, who lives with him, drove to work. Mollie agreed to dog-sit while he was gone.
• At around 5:30 p.m. on July 17, Mollie’s brother, Jake Tibbetts, who shares a car with her, dropped her off at Dalton’s home. Mollie stayed alone while watching the dogs.

July 18

• Investigators report another neighbor reported Mollie out for a jog at around 7:30 p.m. on July 18.
• Mollie had plans to go to her mother’s house for dinner on the evening on July 18. She never showed up.
• At 10 p.m. on July 18, Dalton opened the SnapChat message from Mollie. He said it looked like she took the photo while indoors. It’s unclear when Mollie took the picture but detectives think she took it at some point on Wednesday.

July 19

• Jake Tibbetts, who has been cleared as a suspect, sends Mollie a text message at 7:30 a.m., asking if she needed the car for work. The text message was not read.
• Dalton sends Mollie a text message, wishing her a good morning. Mollie does not read the text message.
• Mollie’s mother, Laura Calderwood, sends Mollie several text messages throughout the afternoon. All text messages remain unanswered.
• Jake Tibbetts calls Laura Calderwood and says Mollie never made it to work at a daycare center. Laura calls the police.

July 20

• The Facebook group, “Finding Mollie Tibbetts,” was created. It currently has over 40,000 members.
• Hundreds of people show up in the Brooklyn area to search for Mollie.
• The Poweshiek County Sheriff’s Office announces that tips should directed to its office.
• The University of Iowa released a statement on Twitter that the school is also monitoring the incident and looking for any helpful information.

July 22

• Authorities announce Mollie is still missing and that nothing was found during the searches.

July 23

• Dalton tells ABC he’s optimistic about Mollie’s return.
• Laura Calderwood says her daughter is an “outgoing, fun, loving life, loving person.”
• Poweshiek County Sheriff Thomas Kriegel announces that no one from the “tight-knit” community in Brooklyn has been missing this long.

July 25

• Investigators continue to follow up with tips and leads.
• The family spreads the search even further by distributing flyers across the state.
•  Kriegel indicates Mollie could have possibly been abducted.

July 26

• Investigators search two hog farms after following up on tips, but the searches yield no results.
• Wayne Cheney is questioned by the FBI.
• Authorities search Cheney’s home and cellphone.

July 27

• Iowa Department of Public Safety released a statement announcing that there are still no suspects but authorities will continue to pursue leads and investigate.
• A neighbor tells a local media outlet that he spotted Mollie “walking nonchalantly” down the street.

August 2

• As authorities searched an area close to the Lincoln Wildfire Reserve in Brooklyn, Iowa, someone mowing their lawn nearby discovered a red a shirt.
• The shirt was turned over to the FBI for evidence processing.
• FBI reportedly asked Cheney to take a lie detector test. He refused.

August 3

• An FBI agent goes to Cheney’s house for a second round of questioning.

August 5

• Authorities revealed there have been “hundreds” of leads and tips into Mollie’s disappearance.
• An Iowa woman’s body was found in Lee County, but despite speculation, police confirmed it was not Mollie, but instead a young woman named  Sadie Alvarado, who allegedly jumped out of a moving car while arguing with her boyfriend.

August 6

• Rob Tibbetts explained why his daughter, according to his own speculations, may still be alive.

Mollie has long brown hair and brown eyes, weighs around 120 pounds and stands 5-feet-2 inches tall. She was last seen wearing running shoes, a pink sports bra, and dark running shorts.

Anyone with any information is urged to contact Crime Stoppers at 800-452-1111.

[Feature Photo: Mollie Tibbetts/Handout]