Investigators have combed through evidence, vetted tips and scoured the area surrounding the small city.
Nearly five weeks to the day since Mollie Tibbetts was last seen going for a run near her boyfriend’s home in Brooklyn, Iowa, remains of the 20-year-old college student have been found. Cristhian Rivera, 24, an undocumented immigrant, faces a charge of first-degree murder in her death.
Investigators had spent weeks combing through evidence, vetting tips and scouring the area surrounding the small city, located about 60 miles east of Des Moines, after the University of Iowa student failed to show up for work on July 19.
Below is a timeline of the investigation:
Monday, July 16
Mollie Tibbetts is seen in person for the last time by her boyfriend of two years, Dalton Jack, he told reporters.
Tuesday, July 17
Jack told reporters he left his home at about 5 a.m. to drive to his job at a construction company located about 50 miles away. Tibbetts was to stay at his home and watch his dog while he was out of town for work.
Wednesday, July 18
Tibbetts was seen during the day out on a run wearing gym shorts, a black sports bra and running shoes, loved ones told reporters.
An avid runner who liked to track her progress, Tibbetts likely would have taken her phone and worn her Fitbit, which logs steps and distance a runner travels, her family said.
Jack said he opened a Snapchat message from Tibbetts, who appeared to be inside when she took the photo. He opened the message about 10 p.m., but the time the photo was taken is not clear.
Thursday, July 19
Jack sent Tibbetts a message, but it went unread. Jack later realized she never looked at the message, he said. Later that day, Tibbetts’ co-worker called Jack to tell him she never showed up for work and didn’t call in sick.
Worried about his girlfriend, Jack called Tibbetts’ loved ones, who hadn’t heard from her at any time on Thursday. Tibbetts’ family then reported her missing to police.
Friday, July 20
Concerned loved ones create the Finding Mollie Tibbetts Facebook group in an effort to bring her home quickly and safely. The group is used to distribute fliers and organize searches. As of Aug. 8, the three-week anniversary of Tibbetts’ disappearance, more than 58,000 people had joined the group.
The University of Iowa, where Tibbetts is a psychology major, also released a statement that they are monitoring the situation and will help in any way possible.
“Our thoughts are with Mollie Tibbetts’ family and friends,” the University said.
Saturday, July 21
Authorities interviewed more than 100 people and continued to search the area for Tibbetts.
Nearly every business in Brooklyn had posted fliers with Tibbetts’ face and name on them in their windows. Search efforts concentrated on four quadrants surrounding Brooklyn, authorities said.
Investigators were also reportedly searching Tibbetts’ laptop and were working on getting warrants for her social media accounts and to obtain data from her Fitbit, as they were unable to rule out foul play in her disappearance.
“Everything’s on the table, unfortunately,” Poweshiek County Sheriff Thomas Kriegel told KCCI-TV.
Sunday, July 22
Celebrities and locals took to social media to spread the word about Tibbetts’ disappearance in hopes she would be found. Tweets from notable figures included actor Tom Arnold, NBA player Harrison Barnes, "Legends of Tomorrow" actor Brandon Routh, Maddie Poppe, winner of season 16 of "American Idol,” and "Workaholics" star Adam Devine.
“If you know something say something!” he urged.
Monday, July 23
Tibbetts’ loved ones continued efforts to reach her directly and through the media.
"I miss you so much, and I love you,” Jack said directly to his girlfriend.
Tibbetts’ mother, Laura Calderwood, told reporters her daughter was preparing to move in to her first apartment and was looking forward to attending Jack’s brother’s wedding in the Dominican Republic on Aug. 2.
"[There are] no words to describe how you feel when you don't know where or how your child is,” she told ABC News.
Investigators had expanded their search for Tibbetts to include cornfields surrounding the community. Searches were being conducted on foot, by plane, by helicopter and in the water by searches in kayaks.
Tuesday, July 24
Volunteer search efforts in the area were called off, as the FBI and state investigators took over the case.
Wednesday, July 25
Poweshiek County Sheriff Thomas Kriegel confirmed to ABC News that Jack and his brothers had been cleared as suspects in the case.
Thursday, July 26
Police said a witness in Missouri reported a possible sighting of Tibbetts at a local truck stop.
Authorities confirmed they had searched a hog farm in the area but had not found anything.
Saturday, July 28
New evidence revealed Tibbetts was doing homework on her computer late into the evening July 18, loved ones told KCCI-TV.
Authorities declined to release a specific time, saying it could hinder the investigation.
Tuesday, July 31
Officials at a press conference said they were confident with the timeline they had established for the day Tibbetts disappeared, but provided little new information as they appealed to the public for help.
“We understand people want to know details about the investigation,” said Kevin Winker, director of investigative operations with the Iowa Department of Public Safety. “Everybody wants to find Mollie. At this point, we’re doing everything we can to make that happen."
Wednesday, Aug. 1
Tibbetts’ father appealed to the public for information.
“The bottom line is somebody knows something,” Rob Tibbetts told Fox News Channel.
He noted that his daughter’s phone had not yet been found and she had not responded to any messages.
Jack, Tibbets’ boyfriend, said she may have left the doors to his home unlocked, noting there had never before been a reason to keep them locked.
“It’s Brooklyn; nothing ever happens in Brooklyn," he said. "That’s why it’s just a blindsided situation."
Wayne Cheney, whose farm had been searched by investigators, told reporters he had been questioned for two hours.
Thursday, Aug. 2
The Iowa task force investigating the claim that Tibbetts had been spotted at a truck stop determines the woman was not Tibbetts. The potential sighting fueled hope and was heavily discussed online.
Search teams scan ditches for traces of Tibbetts near a farm investigators searched a week prior after someone mowing their lawn reportedly found a red shirt not unlike the shirts worn by employees at the day care where Tibbetts worked. Police did not comment on the shirt.
That same day, Tibbetts’ mother made an impassioned plea for her daughter's safe return.
"We believe that Mollie is still alive, and if someone has abducted her, we are pleading with you to please release her," Calderwood said.
Calderwood said she still feels her daughter’s presence.
"Sometimes I just feel her sitting on my shoulder," she said. "Mollie was an incredibly strong young woman, and I don't know that I have the strength in me but Mollie is lending me her strength every day, every night."
Friday, Aug. 3
Authorities held another press conference, but were unable to release any further details about the case.
“Although we appreciated everyone that showed up today to this press conference, our position has not changed on the release of case facts, results and conclusions," Winker said. "I understand this is frustrating for many in the public and the media, but feel this is necessary for our investigation."
Investigators were continuing to treat the case as “a missing persons investigation,” he said.
The FBI reportedly returned to Cheney's farm that day and were seen speaking to the farmer for about five to 10 minutes.
Saturday, Aug. 4
Cheney spoke to Fox News, saying the FBI had searched his home and parts of his property, and looked through his cellphone. He said he would allow investigators to search his entire property, but that he had refused to take a polygraph test.
Cheney reportedly said he thought taking a lie-detector test was “stupid.”
He refused to elaborate to Inside Edition’s Steven Fabian, who found Cheney on his riding mower.
“No. Nothing to say,” he told Fabian, adding that he knew nothing about Tibbetts' disappearance.
Cheney’s ex-girlfriend Judy Johnston, who said she dated him for 18 months, described the farmer as controlling.
"He wouldn't let me talk to anybody," Johnston said. "He would scream at me a lot."
She said that after they broke up, Cheney stalked her and her daughters. She filed a restraining order against Cheney, who in 2014 pleaded guilty to stalking in violation of a no contact order.
Cheney is not considered a suspect in Tibbetts' disappearance.
Sunday, Aug. 5
Searchers looking to Tibbetts discovered the body of a young woman along the side of a rural Iowa road. She was later identified as 20-year-old Sadie Alvarado, whose boyfriend, Damian Hamann, told authorities she jumped out of his car as they argued, according to a criminal complaint filed by the Lee County Sheriff’s Office.
Hamann said he didn’t stop, but instead went home to Morning Sun and returned with his vehicle to the road where Alvarado jumped out of the car to look for her around noon Sunday, the complaint said.
It was not immediately clear how Alvarado died. An autopsy was scheduled at the University of Iowa’s Decedent Car Unit and the case remains under investigation.
Hamann was arrested and charged with leaving the scene of an accident that resulted in death.
That same day, a woman who lives a block away from Tibbetts’ boyfriend told Fox News that she saw a black SUV circling the neighborhood on the night the college student vanished.
The driver went very slowly around the neighborhood between 11:30 p.m. and 1 a.m., according to the woman, who said she reported the sighting to the FBI.
Monday, Aug. 6
Rob, Tibbetts’ father, said he believes his daughter is alive and with someone she knows.
"My two cents is that no one went into that house to hurt her,” Rob told Fox News. “That there was some kind of misunderstanding about the nature of their relationship and at this point they don't know how to get out from under this.”
The reward for information leading to Mollie's return reached $260,000.
Wednesday, Aug. 8
The reward for information rose to $300,000, as Tibbetts’ loved ones shared new videos that showed her carefree spirit.
In one of the videos, Tibbetts can be seen laughing and posing for the camera, and in another, she danced and ran across a gym floor.
Thursday, Aug. 9
A Brooklyn resident spoke about seeing Tibbetts the night she went missing, saying he may have been the last person to see her before she vanished.
“I wish I did know more, but I dread that maybe I was the last person to see her,” Devin Riley told ABC News.
Riley said that when he realized the person he saw jogging by his home looked like the missing woman, he contacted authorities.
“I remembered seeing her that night,” he said. “I just felt very weird. Who knows when she was taken in that timeline, but I don't know what happened."
Sunday, Aug. 12
A former FBI profiler said she believed Tibbetts likely left with someone she knew.
"I think the most likely scenario is that Mollie was at least somewhat familiar with the person that she went with, or the person that she went with was someone that she viewed as non-threatening to her," Marry Ellen O’Toole told KCRG-TV.
That night, loved ones gathered for a prayer service at Corpus Christi Catholic Church in Piedmont, California, where Tibbetts lived with her family as a young child.
"If we lived in Iowa, we'd be searching the corn fields with her family or making meals for the volunteers, but all we can really do is share on social media, pray and just keep the story going," Kathleen Boyle, who helped coordinate Sunday prayer service, told reporters.
Monday, Aug. 13
Authorities established a website to take tips from the public, hoping to stir the memories of residents who may have seen something the night she disappeared.
The website, findingmollie.iowa.gov, allows visitors to leave anonymous information and contains an interactive map of locations, including a truck stop and a general store, in the small town of Brooklyn, asking anyone in the vicinity of those sites on the night of July 18 to contact authorities.
“Mollie is a sensitive, respectful young lady,” said Iowa Division of Criminal Investigation agent Mitch Mortvedt. “She’s an outstanding student who is well-liked by her professors and classmates. Her disappearance is completely out of character for her.”
Tuesday, Aug. 15
After receiving an overwhelming number of tips since creating a website dedicated to finding Tibbetts, authorities were forced to set up a second server just to keep the page online.
“There’s been a lot of activity, to the point where the administration office for the State of Iowa had to get another to server to handle the volume,” Mitch Mortvedt, an assistant director at the Iowa Division of Criminal Investigation, told WHO-TV on Tuesday.
The website highlights five locations of interest in and around Brooklyn.
Wednesday, Aug. 16
Investigators on Wednesday denied a sensational RadarOnline report claiming police are closing in on potential suspects.
The report, published Aug. 15, cited a source close to the FBI, who said detectives believed a person who abducted Tibbetts attended a vigil for her.
Mortvedt, the assistant director at the Iowa Division of Criminal Investigation, told Fox News he had "not heard that from anyone or anywhere.”
Authorities are aware of the RadarOnline report but its "authenticity has not been verified," Rick Rahn, a special agent in charge at the Iowa Division of Criminal Investigation, told Fox News.
No suspects or persons of interest have been announced in Tibbetts' disappearance.
Meanwhile, Vice President Mike Pence, who was visiting Iowa to promote President Trump's tax cuts, took the opportunity to meet with the Tibbetts family to pray Wednesday.
Saturday, Aug. 18
Tibbetts' father, Rob, said law enforcement officials have told him to return home.
"Very reluctantly, I'm being told I sort of need to do this," Rob told KCRG-TV9. "We've called this sort of a halftime, a break."
The Tibbetts family have been encouraged to “return to their day-to-day lives and leave them in charge of the case,” according to the station.
Tuesday, Aug. 21
Tibbetts was found dead. An undocumented immigrant, 24-year-old Cristhian Rivera, has been charged with her murder, officials said.
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