Family and friends of 20-year-old college student Mollie Tibbetts endured weeks of mystery after she vanished from her small town of Brooklyn, Iowa

Family and friends of 20-year-old college student Mollie Tibbetts endured weeks of mystery after she vanished from her small town of Brooklyn, Iowa, in mid-July — having last been seen alive out on her regular evening run

On Tuesday, a police source told PEOPLE that Tibbetts’ dead body was found, more than a month after she was reported missing in Brooklyn.

While the police source said the body was found Tuesday morning in a field in Poweshiek County, where Tibbetts lived, additional details about the discovery were not immediately available.

Confirmation is pending on the remains but authorities are confident that they belong to Tibbetts, according to the source.

A news conference about the case is scheduled for later Tuesday. Investigators have so far declined to release much information about their work.

The discovery of a body marks a grim end to the search for Tibbetts, which captured national attention as a reward fund for information leading to her safe return broke records in Iowa, with hundreds of thousands of dollars pouring in.

Her death is an answer to the question of her disappearance that loved ones hoped never to see.

“We know that Mollie knows how much we love her and how important she is to her entire family,” her cousin Emily Heaston previously told PEOPLE. “We want her to know that we will never stop looking for her.”

Speaking after the announcement that Tibbetts had died, friend Alyssa King said, “We are all devastated.”

Here’s what we know about the case so far.

Mollie Tibbetts
| Credit: Poweshiek County Sheriff's Office

1. Tibbetts Was Dog-Sitting When She Decided to Go for a Run — the Last Time She Was Seen

The last time anyone saw Tibbetts was around 7:30 p.m. on July 18, as she was jogging in Brooklyn, a community of some 1,500 people in eastern Iowa, authorities said. She was wearing dark-colored running shorts, a pink athletic top and running shoes.

Tibbetts had been dog-sitting but headed out for some exercise as part of her typical routine, according to her boyfriend, Dalton Jack.

She reportedly sent him a photo on Snapchat that he opened later that night.

Then she vanished.

“It’s Brooklyn. You don’t lock your doors,” Jack told Fox News. “We lock our doors now. Every night.”

He has reportedly said he first learned Tibbetts was gone on the afternoon of July 19, when one of her coworkers called and said she “had not called into work that day and she hadn’t showed up.” He’d texted her that morning but got no response.

“And then I looked at the messages and she hadn’t opened or read the message,” Jack said. “And then I started getting in contact with her friends and family, saying, ‘Have you seen her or heard from her?’ And they all said the same thing: ‘No, we haven’t heard from her since yesterday.’ ”

Tibbetts was reported missing that same day by her family.

Weeks later — perhaps longer than any missing-persons case has lasted in the area — it remains unclear why, how or where she disappeared or who may be responsible.

“Everything and everybody” is under review, the county sheriff, Thomas Kriegel, previously told PEOPLE.

State authorities confirmed that was still the case at an Aug. 3 news conference, saying, “We continue to look at all possibilities.”

Mollie Tibbetts

2. Her Boyfriend Has Been Ruled Out as a Suspect

Jack, Tibbetts’ boyfriend of nearly three years, has been cooperating with investigators, who have formally excluded him as a suspect, authorities previously told PEOPLE.

In early August Tibbetts should have attended a destination wedding in the Dominican Republic, where she and her boyfriend had planned to watch his brother get married on the beach.

Instead the ceremony was canceled as Tibbetts’ stunned loved ones searched for answers in her mysterious disappearance, according to the Associated Press.

Tibbetts and Jack were scheduled to attend the nuptials of his 23-year-old brother, Blake Jack, the AP and CBS News report. Blake had even said — jokingly — that it was there that Dalton should propose to Tibbetts.

Black addressed his missing girlfriend in an interview with the Des Moines Register published July 24, saying, “I miss you so much and I love you.”

Speculation that Tibbetts could not have been abducted by a stranger is misguided, Mitch Mortvedt, a spokesman for the Iowa Division of Criminal Investigation, previously said.

“One avenue of thought is that if it wasn’t a struggle, and we have found no signs of a struggle, then maybe it was someone she was familiar with,” Mortvedt told PEOPLE. “But then the other avenue of thought is it could have been a stranger who simply overpowered her or tricked her. We just have very little to go on.”

Mortvedt did confirm to PEOPLE that investigators were interviewing a number of people Tibbetts knows or seems to “have a connection to,” including other University of Iowa students and her co-workers.

Mollie Tibbetts

3. Searchers Have Covered the Area by Ground, Water and Sky

At the Aug. 3 news conference, Kevin Winker, the director of investigative operations for the Iowa Division of Criminal Investigation, outlined in general terms the expansive sweeps conducted so far for Tibbetts.

“We have been searching ponds, fields and even from the air, so we’ve been doing searches in many different manners,” he said.

A massive ground search involving more than 200 people broken up into 37 teams was conducted on July 20 encompassing the farmlands and fields within a five-mile radius of Brooklyn, with helicopters hovering above, according to authorities.

Kayakers were also directed to probe two small rivers for clues, Sheriff Kriegel previously said, and other local bodies of water were searched. On July 26, detectives searched a pig farm in Guernsey, Iowa, which is about 15 minutes by car from Brooklyn.

Investigators have also reviewed extensive surveillance footage from the area as well as Tibbetts’ digital footprint — including her social media activity and data from her fitness tracker, according to her family and law enforcement.

4. Authorities Are Keeping Mum About Key Questions but Have a ‘Solid Timeline’

A lot is still publicly unknown in Tibbetts’ case. While authorities have stayed tight-lipped about several key questions in the investigation, they said earlier in August that they were not slowing down.

Asked if authorities knew when and where, exactly, Tibbetts was when she went missing, Kevin Winker with the Iowa DCI instead confirmed that they were working from a “solid timeline” in her disappearance but he did not elaborate.

Beyond that, he declined to discuss most parts of the ongoing investigation such as whether or not there were suspects.

Repeatedly Winker said he was unable to discuss questions about whether or not physical evidence had been located, such as Tibbetts’ clothing, which exact locations had been searched and other inquiries about the investigation’s work and direction.

Winker acknowledged that while some information has been released, the lack of full clarity for the public about what was known in the case can be frustrating.

But, he said, officials believe their reticence so far “gives us the best opportunity to resolve the investigation.”

Mollie Tibbetts (bottom) with relatives
| Credit: Courtesy Emily Heaston

5. Loved Ones Aren’t Staying Silent

Tibbetts had a personality to match the beaming smile she showed off in so many photos, according to her friends and family.

“She really does not have a single enemy — everybody loves Mollie,” Alyssa King, who has known Tibbetts for years, told PEOPLE. She described Tibbetts as always there when she was needed and “always trying to make people laugh.”

Breck Goodman, an incoming University of Iowa freshman, said Tibbetts helped her decide which school to attend this fall: “As always, she was very helpful, very kind and very nice about it.”

Goodman was friends with Tibbetts for more than five years and considered her one of her closest confidants.

“We talked about everything and anything and agreed on most subjects — everything from politics and social justice to typical teenage girl stuff like boys. … She is such a caring person,” Goodman said.

Jack, Tibbetts’ boyfriend, told ABC News she was “kind, sweet, caring, she’ll do anything for everybody.”

Aunt Kim Calderwood called her “beautiful” and “positive” — “a very responsible and conscientious young woman,” according to local TV station WOI and the Des Moines Register.

Tibbetts was on the debate and track teams in high school and was a presence at her church, the paper reports.

“She’s strong and sassy and a fighter and stubborn,” her aunt said, according to the Register, “and she is not a quitter.” Cousin Emily Heaston echoed that to PEOPLE, previously saying Tibbetts “comes from a long line of passionate, strong and talkative women.”

Goodman said the entire ordeal had been “heartbreaking for me.”

Speaking with ABC in July, Tibbetts’ mom used another word: “excruciating.”