As the FBI continues its manhunt for Brian Laundrie near his home in Florida, it is possible the experienced outdoorsman has an almost two-week headstart into the wilderness.
The hiking enthusiast is being sought by police after his girlfriend Gabby Petito, 22, was found dead in Wyoming, with an autopsy saying it is likely she was murdered.
He is officially wanted on an arrest warrant for using Petito's credit card. He has been described as a "person of interest" in the missing person case of Petito.
Laundrie has not been seen for 10 days – long enough for him to disappear far away from his parents home in North Port, on the Florida Gulf Coast.
But there is a suspicion as to where he has headed – the Appalachian Trail, or AT. It's a renowned 3500km trail between Georgia and Main in the eastern US.
Both he and his fiancee had a fondness for the region.
Petito shared photos on Instagram in March from the Appalachian Trail near where it commences its run at Springer Mountain in northern Georgia's Blue Ridge Mountains.
On her page @gabspetito – where follower numbers have grown to one million – she posted on March 27 that she went hiking there for her 22nd birthday.
In July last year, Laundrie posted an image of himself on a different trail, in Colorado, but wrote on it: "I've hiked hundreds of miles on the AT."
A 3500km trail from Georgia to Maine
Laundrie spent his entire childhood in New York State, mostly at Sayville near Bay Point on Long Island, where he and Petito went to school, a grade apart.
His mother, Roberta Laundrie, was a government employee for the Suffolk County Department of Health – Office of Water Resources on Long Island for years.
It is believed that while living there Laundrie accessed the 3500km AT nearer its northern end, at Mt Katahdin, Maine.
The AT passes through several parks in New York State, with connector trails accessible via train stations and roads. It also features camping grounds and hiking shelters.
It is from Bayport, Long Island that Petito and Laundrie embarked on a tour in a van she owned after farewelling her family who live there in late June this year.
If Laundrie has indeed now headed for the Appalachian Trail from its southern end, he could access it via a number of feeder trails, which are hundreds of kilometres and many days' walk from Florida.
From the Pinhoti trail to Springer Mountain in Georgia, it is 110km of walkable terrain at an average speed of 5km/h.
Differences between Instagram and real life
The YouTube "Van Life" video shot and edited by Laundrie and Petito on their seemingly idyllic odyssey through America's great wilderness spots portrays Laundrie as a calm and peaceful man.
On the video, the couple take in windswept beaches, perfect sunsets and spectacular scenery while feeding each other, kissing while sheltering from the rain, and Laundrie piggybacking Petito.
But the observations by strangers of the pair on the road suggest the reality may have been different to the edited perfection of their lives.
One couple observed Laundrie allegedly slapping Petito on the side of a road in Moab, Utah – after which officers talked to the couple about a possible domestic incident which was captured on police bodycam.
Now a second alleged episode has come to light.
About two weeks after the Moab incident, a New Orleans couple told Fox News they saw Laundrie in an alleged argument with staff at a restaurant in Jackson Hole, Wyoming on August 27.
This is now the last time Petito was seen alive – at a location just 58km from the remote spot at Spread Creek Dispersed camping area where her body was later found.
Nina Celie Angelo told Fox News she and her boyfriend Matthew England were having lunch between 1pm and 2pm that day at The Merry Piglets, a Tex-Mex restaurant.
They claim they saw an agitated Laundrie arguing with a waitress and other female staff, who have since confirmed the Van Life pair were there.
Angelo said she thought Laundrie was arguing over the bill or about money.
He was "not screaming", she said, but Angelo claimed he was behaving aggressively with the restaurant staff, a waitress, a hostess and the manager, all of whom were women.
Angelo described Laundrie's body language as "aggressive" and said he left and returned about four times, with Petito coming inside to apologise for her boyfriend's behaviour.
Four and a half hours later, a travel-blogging couple passed Petito's van at a campsite north of town in Bridger-Teton National Park, but did not see the couple.
England claimed Petito seemed "visibly upset" with Laundrie as he castigated the Merry Piglets staff.
"I'm 1000 per cent sure that was him and that was her," he said.
Four days after the incident, Laundrie arrived back in Florida at his parents' home without Petito.
Her remains were found at a campsite an hour's drive north of Jackson Hole down a winding road called Sleeping Indian Turn.
More alleged sightings of Laundrie
A TikTok user has told the FBI she saw Laundrie alone and "acting weird" near the Spread Creek site where Petito's body was found.
Jessica Schultz said she was driving behind a white Ford Transit van with Florida plates as it drove slowly down a narrow road. She felt the driver didn't seem to know where he was going.
The van's driver partially pulled off the road, forcing Schultz to drive off the road to get around it.
Looking over at the driver, she noticed he was alone and said he looked like a "generic" white guy.
"He was just acting weird," Schultz, 38, told The Chronicle.
"You know, when you're out in the middle of nowhere, your hackles go up when you see something that's out of the ordinary."
Schultz, who has lived out of her own van for four years, said she was curious about how other van-lifers travelled.
"He was very awkward and confused and it was just him, there was no Gabby," Schultz said on TikTok.
Alleged sightings of Laundrie have been pouring into authorities since it was reported he had left his parents' North Port, Florida home more than a week ago.
But while North Port Police have focused their search on a 10,000-hectare reserve near the town, many are speculating Laundrie may have gone further afield.
Where is Brian Laundrie?
Brian Laundrie's parents, Christopher and Roberta, said their son had gone hiking on his own in Carlton Reserve, a 17-minute drive from North Port.
But Charlene and William Guthrie, who live opposite the Laundrie family, claim that on September 11 – the same day Petito's parents reported her missing – Laundrie and his parents left their home with an RV attached to their vehicle.
Guthrie told Fox News that on that day he watched Christopher and Roberta Laundrie hook what appeared to be a new camper to the back of their truck and drive off with Laundrie.
"I saw them loading the camper," said Guthrie, who found it odd the Laundries would go camping with their adult son in what he described as a "small" RV.
The Guthries said when Laundrie returned to the family home on September 1 in Petito's white van, they assumed his live-in girlfriend was in tow.
They also assumed the van belonged to Laundrie.
"We didn't know it was Gabby's; we just assumed it was [Laundrie's] van," Guthrie reportedly said.
"We just thought they had come back from wherever. We didn't know they were on a trip.
"We assumed they went back to their house or wherever they got a house."
Here are the key dates in Gabby Petito's death and the continuing investigation.
Petito shared photos on Instagram from the Appalachian Trail Georgia and wrote she went hiking there for her 22nd birthday.
Petito visited her family in Long Island, New York, before departing on the trip with Laundrie.
July 2, 2021
The couple set off on their adventure to see some of the most spectacular sights across America.
Laundrie shared an engagement photo on Instagram of the pair dressed in formal wear, which he captioned: "My biggest fear is that one day I'll wake up and it will have all been a dream. Because that is what every second has felt like since the moment we found each other. Til death do us part or until I wake up, I'm so happy the answer was yes, Love you hunny."
Petito shared photos on Instagram from the Monument Rocks in Kansas, using the #vanlife hashtag for the first time.
July 8 – August 12
Petito shared photos on Instagram from Colorado Springs, Great Sand Dunes National Park, Zion and Bryce Canyon national parks, Mystic Hot Springs, Mesa Arch, Canyonlands and Archer National Park.
Laundrie published his last photo on Instagram and tagged it in Utah.
Petito uploaded a video to her YouTube channel and shared a picture on Instagram.
During a conversation on FaceTime, Petito told her mother they were leaving Utah and going to Wyoming.
Petito text messaged her mother and published her last photographs on Instagram.
Petito's mother, Nicole Schmidt, received a suspicious text message from her daughter's phone. Schmidt said her daughter never referred to her grandfather as Stan, so she doesn't believe she sent this: "Can you help Stan, I just keep getting his voicemails and missed calls."
Miranda Baker and her boyfriend believed they gave Laundrie a ride while he was hitchhiking in Colter Bay, Wyoming, and dropped him off near the Jackson Dam.
A licence plate reader detected the white van belonging to Petito at about 10.26am on the North Port, Florida highway exit.
Petito's relatives reported her missing to the Suffolk County Police Department in New York. Laundrie and his parents refused to answer questions from Petito's family or North Port authorities.
Officers searched the 2012 Ford Transit van and Laundrie's parents told police their son left his home with a backpack.
Sarasota County Circuit Court Judge signed a search warrant in the case. Detectives identified Laundrie as a person of interest.
Petito's family made a public plea for help. Officers executed a search warrant at Laundrie's home.
Laundrie's parents reported him missing as of three days earlier. FBI agents issued a missing poster for Petito.
Officials began searching for Mr Laundrie at Carlton Reserve near North Port while the FBI collected evidence at Grand Teton National Park.
FBI reported a body had been found in Wyoming's Bridger-Teton National Forest by a US Park Ranger vehicle driving off US Highway 89, just east of Grand Teton National Park.
FBI agents searched Laundrie's family home in North Port, where he and Petito had been living with his parents, Christopher and Roberta, before departing on their van trip. FBI agents reported human remains found in Wyoming were consistent with Petito's description.
FBI reported that an autopsy had identified Petito's remains. The coroner determined Petito's manner of death was homicide, with the cause of death yet to be determined or released.
As the search continued in the Carlton Reserve, a federal grand jury indicted Laundrie for unauthorised use of a debit card. The indictment did not say who the card belonged to and the nature of the charges have not been disclosed.
As the search in Florida swampland continued for a fifth unsuccessful day, an arrest warrant was issued for Laundrie allegedly over using a Capital One Bank card and someone's personal identification number to make unauthorised withdrawals or charges worth more than US$1000 ($1400) during the period in which Petito went missing. The arrest warrant will allow law enforcement across the country to continue pursuing Laundrie while the investigation continues into Petito's homicide.