Here's a timeline with everything we know so far about the case:
July 2, 2020: Engagement
Exactly one year before they started their cross-country trip, Gabby Petito announced her engagement to Brian Laundrie on Instagram.
December 11, 2020 Van purchased
Gabby announces on Instagram that they have purchased a "garden on wheels! New van means new adventures."
July 2: Petito and Laundrie depart
The couple had been in Blue Point, New York, where Petito is originally from, to celebrate her younger brother's graduation from high school. They departed New York on July 2 on a planned four-month cross-country journey.
According to a Petito family attorney, the pair had gotten engaged, but postponed their wedding plans because of the coronavirus pandemic and decided to take the trip instead.
They were driving Petito's white 2012 Ford Transit van which, according to one of Laundrie's posts on Instagram, they converted the interior to allow them to camp and cook meals inside of as they traveled.
Then, according to their social media posts, the pair traveled from Florida to Kansas, Colorado, and Utah, touring and camping at several national parks and natural attractions.
ORIGINAL REPORT: 'We don't eat, we don't sleep, we're just actively looking for her.'
July 4-August 11 The Journey
According to Gabby's Instagram timeline, the couple stopped in these locations:
July 4: Monument Rock, Kansas
July 8: Colorado Springs, Colorado
July 10: Great Sand Dunes National Park and Preserve, Colorado
July 16: Zion National Park, Utah
July 21: Bryce Canyon National Park, Utah
July 26: Mystic Hot Springs, Utah
July 29: Canyonlands National Park, Utah
August 12: Arches National Park, Utah
August 12: Moab City, Utah 'altercation'
In August, police in Moab, Utah had an encounter with Petito and Laundrie and the pair was described as having "engaged in some sort of altercation," according to a report released by the Moab City Police Department.
Moab City police were called to reports of disorderly conduct on August 12 and encountered Laundrie and Petito, along with a witness whose full name was redacted from the report.
Laundrie and Petito are described as having gotten into a physical fight following an argument, but "both the male and female reported they are in love and engaged to be married and desperately didn't wish to see anyone charged with a crime," according to the report from Officer Eric Pratt.
At the officers' suggestion, Laundrie and Petito separated for the night, the report said. Petito is described by one officer as "confused and emotional."
"After evaluating the totality of the circumstances, I do not believe the situation escalated to the level of a domestic assault as much as that of a mental health crisis," Officer Daniel Robbins wrote in the police report. No charges were filed.
Robbins wrote Laundrie said the pair had been traveling together for "the last 4 or 5 months."
MORE: Police body cam video shows Gabby Petito, boyfriend after 911 call
August 17-23: Brian flies to Florida
Laundrie family attorney Steven Bertolino confirms Brian Laundrie flew home to Tampa from Salt Lake City on August 17 and flew back to Salt Lake City on August 23 to "rejoin Gabby."
Bertolino says Brian flew home to "obtain some items and empty and close the (couple's) storage unit to save money as they contemplated extending the road trip." Bertolino says the couple paid for the flights together, as they were sharing expenses.
August 27: Fight at Wyoming restaurant
A woman named Nina Celie Angelo took to her Instagram saying she witnessed Gabby Petito and Brian Laundrie get into an explosive argumentat the Merry Piglet restaurant in Jackson Hole, Wyoming. She said Laundrie was screaming at the hostess, and Petito was in tears and apologizing.
"It looked as though they were like almost getting kicked out," Angelo told ABC News. "It wasn't necessarily between them, it was more so Gabby abruptly leaving the restaurant crying, and Brian was just evidently really upset, pissed off, I would say. I would say Gabby was upset, he was angry, and he was just being very temperamental towards the restaurant staff."
Angelo said Laundrie was "very visibly angry," and Petito seemed distraught. This is the last known sighting of the couple together.
August 30: Last communication with family
Petito's mother, Nichole Schmidt, said the last text message she received from her daughter came on August 30. She said she was unsure if it was her daughter actually sent those text messages.
According to a warrant filed by the North Port Police Department weeks later, a detective wrote that Petito's mother "received an 'odd text' from Gabby. The text message read 'Can you help Stan, I just keep getting his voicemails and missed calls.' The reference to 'Stan,' was regarding her grandfather, but per the mother, she never calls him 'Stan.' The mother was concerned that something was wrong with her daughter."
Her family said that final message was "not normal behavior" for Petito and became more worried about her, according to police.
September 1: Laundrie returns to North Port
Laundrie allegedly returned to the North Port home he and Petito shared with his parents on September 1.
Police said he had driven the couple's van there and Petito was not with him.
ALSO READ: Boyfriend of missing Gabby Petito issues statement through lawyer
September 11: Family reports Petito missing
On September 11, Petito's family reported her missing to the Suffolk County Police Department in New York at approximately 6:55 p.m.
When police in Florida knocked on the Laundrie's door that night, his parents handed them a lawyer's phone number.
"We don't know what Brian knows, that's the bottom line," Taylor said. "We are hopeful to talk to him. He needs to talk to us. We need to know exactly where he was, where she was, their last locations, and the fact he was back here for 10 days. Again, the family reported her missing 10 days later. "
Their van was processed for evidence, and Taylor said there were some materials that will be investigated further.
September 15: Laundrie named person of interest
On Wednesday, Laundrie was officially named a person of interest in Petito's disappearance and North Port Police said he was hindering the investigation.
Laundrie has not made himself available to be interviewed by investigators or provided any helpful details.
His attorney issued the following statement on behalf of his client, addressing Laundrie's silence.
"Many people are wondering why Mr. Laundrie would not make a statement or speak with law enforcement in the face of Ms. Petito's absence. In my experience, intimate partners are often the first person law enforcement focuses their attention on in cases like this, and the waring that 'any statement made will be used against you' is true, regardless of whether my client had anything to with Ms. Petito's disappearance. As such, on the advice of counsel, Mr. Laundrie is not speaking on the matter. I have been informed that the North Port, Florida, police have named Brian Laundrie as a 'person of interest' in this matter. This formality has not really changed the circumstances of Mr. Laundrie being the focus and attention of law enforcement, and Mr. Laundrie will continue to remain silent on the advice of counsel."
DETAILS: PD: Missing woman's fiancé a person of interest, hindering search
September 16: North Port press conference with father, Petito family letter
Police in North Port held a news conference during which Petito's father begged for her safe return -- and for Laundrie to speak up and stop hindering the investigation.
Later, Petito/Schmidt family attorney Richard Stafford read aloud a letter to Laundrie's parents pleading for their son to speak to them about Gabby's disappearance.
September 16/17: Laundrie's sister speaks to "Good Morning America"
Hours after the family of 22-year-old Gabby Petito issued a statement to the family of her fiancé, begging for information in her disappearance, Brian Laundrie's sister, Cassie Laundrie, broke her silence in an exclusive interview with GMA.
"Obviously me and my family want Gabby to be found safe," she said. "She's like a sister and my children love her, and all I want is for her to come home safe and found and this to be just a big misunderstanding."
September 17: No connection to double-homicide case
Despite earlier speculation, authorities in Utah announced Friday that Petito's case has no connection and is not related to the double-homicide case involving Crystal Turner and Kylen Schulte.
September 17: Laundrie family reports Brian missing
Police said Laundrie's attorney contacted authorities Friday because the family wanted to discuss his disappearance.
They claimed they had not seen Brian since Tuesday.
They removed items from the Laundries' house to assist in the search for him, according to his attorney Steven Bertolino.
Police said on Twitter that it was the first time the Laundrie family had spoken with them in detail about the case.
They reiterated that Brian is a person of interest in Gabby's disappearance, but that they are "not currently working a crime investigation."
Both he and Petito are now considered missing persons.
September 18: Dual searches for Petito, Laundrie
Police searched a vast Florida wildlife reserve on Saturday for 23-year-old Brian Laundrie, a person of interest in the disappearance of his girlfriend, Gabrielle "Gabby" Petito, while across the country the FBI hunted for clues about the missing woman in a mountainous national park in Wyoming.
The search was called off Saturday night by North Port Police due to darkness. They say nothing was found.
Our search of the Carlton is being called this evening due to darkness. Nothing found. Efforts will begin again Sunday morning. pic.twitter.com/l7L8B9hHrM— North Port Police (@NorthPortPolice) September 18, 2021
Meanwhile, the FBI in Denver said Saturday that agents were conducting ground surveys at Grand Teton National Park in Wyoming, with help from the National Park Service and local law enforcement agencies, seeking clues to Petito's disappearance. Her last known contact with family members was from the national park known for its mountainous terrain.
The #FBIDenver Field Office and its Wyoming Resident Agencies, in coordination with the National Park Service, U.S. Forest Service, Teton County Sheriff's Office & Jackson Police Department, have been conducting ground surveys at the Spread Creek Dispersed Camping Area. pic.twitter.com/95HjWcEuDU— FBI Denver (@FBIDenver) September 19, 2021
September 19: Body found in Wyoming believed to be Gabby Petito
Authorities say a body discovered Sunday in Wyoming is believed to be Gabrielle "Gabby" Petito. The FBI said the body was found by law enforcement agents who had spent the past two days searching campgrounds. An FBI agent said the cause of death not yet been determined.
Petito's family was notified. Her father tweeted a short time later.
Aerials near site where remains found in search for Gabby Petito
Laundrie has been identified as a person of interest in the case. He was last seen by his family in Florida on Tuesday and investigators have been searching for him.
September 20: Laundrie Family Home Searched
Police and FBI agents armed with a search warrant swarmed the Florida home Brian Laundrie shared with his parents.
A 911 call from a witness who claimed he saw Brian Laundrie "slapping" Gabby Petito and chasing her up and down a sidewalk was also released. The call prompted police to pull the couple over on Aug. 12, where the infamous police body camera footage of Petito upset.
September 21: Autopsy confirms body found is Gabby Petito
An autopsy confirms body found in Wyoming is Gabby Petito, family attorney says, as the manhunt for Brain Laundrie continues in Florida.
Teton County Coroner Dr. Brent Blue's initial determination is Petito's death is a homicide. The cause of death remains pending final autopsy result.
Teton County Coroner Dr. Brent Blue confirmed the remains are those of Gabrielle Venora Petito, date of birth March 19, 1999. Coroner Blue’s initial determination for the manner of death is homicide. The cause of death remains pending final autopsy results. pic.twitter.com/JoHenMZ9UU— FBI Denver (@FBIDenver) September 21, 2021
Investigators returned to a massive Florida nature preserve to search for Laundrie on Tuesday. He remains at large.
September 22: Divers join the search for Laundrie
Search teams returned to a Florida nature park to look for Laundrie. North Port police spokesperson Joshua Taylor says the search resumed around 8 a.m. Wednesday at the 24,000-acre wilderness park.
RELATED: Legal analysis: Why police haven't issued an arrest warrant for Brian Laundrie in Gabby Petito case
Investigators say Brian Laundrie's parents told them he had gone there after returning home without Petito on Sept. 1.
A dive team joined the search, which includes thousands of acres of forbidding, swampy subtropical terrain replete with alligators, snakes, turkey, deer and other wild creatures. There are more than 100 miles of hiking and horseback riding trails.
September 23: Arrest warrant issued for Laundrie
A federal arrest warrant was issued for Brian Laundrie in connection with his activities after the death of Gabby Petito.
The U.S. District Court of Wyoming issued the warrant and indictment on Wednesday, related to Laundrie's unauthorized use of a Capital One debit card and pin code with "intent to defraud" between Aug. 30 and Sept. 1 in Wyoming and elsewhere with a value of $1,000 or more.
On September 22, 2021, the U.S. District Court of Wyoming issued a federal arrest warrant for Brian Christopher Laundrie pursuant to a Federal Grand Jury indictment related to Mr. Laundrie’s activities following the death of Gabrielle Petito. pic.twitter.com/SSrBVbAeBs— FBI Denver (@FBIDenver) September 23, 2021
Meanwhile, a fifth day of searching at a massive wilderness park in Florida yielded no results in the manhunt for Laundrie.
September 25: Rewards for Laundrie's wereabouts
As the search for Laundrie stretched into its second week, two separate rewards totaling $30,000 have been offered to anyone who provides law enforcement officials with Laundrie's whereabouts.
September 26: Memorial service held for Gabby Petito
The family and friends of Gabby Petito gathered in Holbrook, New York, on Long Island to honor her memory, one week after the 22-year-old's remains were found in a national forest in Wyoming.
In a eulogy, Joseph Petito described his daughter as a "happy girl," who people would gravitate toward. She made others feel welcome, he said, and loved adventuring outdoors, whether it was scuba diving or hiking the Appalachian Trail.
"I want you to be inspired by Gabby, that's what we're looking for," Joseph Petito said. "If there's a trip that you guys want to take, take it now. Do it now while you've got the time.
"If there's a relationship that you're in that might not be the best thing for you, leave it now," he said, an apparent reference to his daughter's relationship with Laundrie.
Petito's stepfather, Jim Schmidt, also gave eulogy, telling those gathered, "Parents aren't supposed to bury their children. That's not how this is supposed to work."
RELATED: 'Gabby Petito Foundation' created to help families of missing children
Richard Stafford, an attorney for the Petito family, said the family is asking for donations to a future Gabby Petito foundation in lieu of flowers.
September 27: Laundrie's parents speak out
The parents of Brian Laundrie say they do not know where their son is and hope the FBI can locate him.
RELATED: What Brian Laundrie was doing after he returned to Florida without Gabby Petito
The statement from their attorney came as the FBI said Monday they will dial down the large-scale search efforts for Gabby Petito's fiancé as the manhunt enters a second week.
Authorities collected personal items from the Laundrie home in Florida in hopes they can use DNA samples to help solve the case.
September 29: Gabby Petito's family holds news conference
Gabby Petito's family held a sometimes emotional press conference as the FBI manhunt continues for her fiancé Brian Laundrie.
Her parents and step-parents showed tattoos designed by Gabby with sayings like "Let It Be" and "Believe" that they had done in her memory.
They avoided answering some questions, particularly about Brian Laundrie. Their lawyer was adamant that Laundrie's parents provided no help finding Gabby, so they were expecting no help from them finding Brian.
September 30: FBI returns to Brian Laundrie home in Florida
FBI agents returned to the Laundrie family home on Thursday. They were seen looking at the camper and going into the home, according to reporters on the scene.
The attorney for the Laundrie family says the FBI is collecting "some personal items belonging to Brian (Laundrie) that will assist the canines in their search for Brian."
According to the attorney at the time, "There is nothing more to this."
September 30: ABC News obtains phone call records
ABC News obtained 46 pages of records from North Port police for "calls of service" at the Laundrie home from Sept. 10 - Sept. 27.
Police say they were not 911 calls and some were initiated by police officers. Two calls were made on Sept. 10, the day before Gabby Petito's parents reported her missing, and three calls were made on Sept. 11, the day she was reported missing.
There is no information on what those calls may have been in regards to.
October 1: New bodycam video of Gabby Petitio
New body camera video was released from a second officer responding to the 911 call of a domestic dispute between Gabby Petito and Brian Laundrie while they were on the road back in August.
Petito looked at visible bruises on her body as the officer questioned her while she sat in the vehicle.
October 5: Gabby's family speaks out on social media
Gabby Petito's family joined Twitter Saturday to post emotional messages and tributes for the 22-year-old, including calls for her fiancé Brian Laundrie to surrender to police.
A chorus of tributes were posted Saturday by Petito's immediate family, many of whom joined Twitter, to remember Gabby, but also to urge her fiancé to turn himself in.
Petito's mother Nichole Schmidt wrote on Twitter, "Mama bear is getting angry. Turn yourself in!"
October 5: Cassie Laundrie pleads for brother to return home
Brian Laundrie's sister, Cassie, spoke out exclusively to ABC News in the wake of her brother's disappearance following the death of his fiancée Gabby Petito. Cassie Laundrie says she last saw her brother at a Florida campsite with her family days before he was reported missing. She said she had no idea anything was amiss and didn't realize at the time that he had returned home from his road trip without Petito.
"I really wish he had come to me first that day with the van, because I don't think we'd be here," she said. "I worry about him. I hope he's OK, and then I'm angry and I don't know what to think."
She pleaded with him to come forward.
RELATED: Brian Laundrie flew home and then back to Utah in middle of road trip with Gabby Petito
"I would tell my brother to just come forward and get us out of this horrible mess," she said.
October 7: Brian's dad joins in the search
Brian Laundrie's father is now joining in the search for his son in connection with the Gabby Petito case.
Law enforcement wants Chris Laundrie to direct them within the Carlton Reserve to a spot where he claims Brian might be hiding.
The family's attorney released a statement: "Chris Laundrie is assisting Law Enforcement today in the search for Brian. Chris was asked to point out any favorite trails or spots that Brian may have used in the preserve. Although Chris and Roberta Laundrie provided this information verbally 3weeks ago it is now thought that on-site assistance may be better. The preserve has been closed to the public and the Laundries as well but the parents have been cooperating since the search began."
October 12: Gabby Petito's autopsy shows she died by strangulation
The autopsy results of Gabby Petito were released at a press conference, nearly one month after her body was found in Wyoming.
Teton County Coroner Dr. Brent Blue announced that Petito's cause of death was ruled as strangulation. "We hereby find the cause and manner of death to be the cause of death by strangulation," he said.
It's estimated that she died about three to four weeks before her body was found.
October 20: Medical Examiner called to park
The Medical Examiner's office in Sarasota has been called to the preserve where the search for Brian Laundrie is underway, a spokeswoman for the office told ABC News.
Brian Laundrie's parents along with the FBI and local authorities found some items belonging to Brian off a trail that he frequented.
October 20: Possible human remains found
Investigators have recovered what appears to be human remains at a Florida preserve near a backpack and notebook belonging to Brian Laundrie.
The FBI confirmed the new details at a briefing in Florida on Wednesday.
"Earlier today, investigators found what appeared to be human remains as well as personal items, such as a backpack and notebook belonging to Brian Laundrie. These items were found in an area that up until recently had been under water," FBI Special Agent in Charge, Michael McPherson said.
October 21: Brian Laundrie's remains confirmed
Dental records prove that remains found in a Florida park are those of Gabby Petito's fiance, Brian Laundrie, according to the FBI.
Laundrie family attorney Steven Bertolino released the following statement:
"Chris and Roberta Laundrie have been informed that the remains found yesterday in the reserve are indeed Brian's. We have no further comment at this time and we ask that you respect the Laundrie's privacy at this time."
Laundrie family attorney speaks out following the discovery of Brian's remains
The developments brings to a close a massive, five-week search for the man sought as a person of interest in Petito's murder.
From the Petito Family attorney: “Gabby’s family is not doing interviews or making a statement at this time. They are grieving the loss of their beautiful daughter. Gabby’s family will make a statement at the appropriate time and when they are emotionally ready.— Kristin Thorne (@KristinThorne) October 21, 2021