Brian Laundrie, 23, who is believed to be on the run after his girlfriend's murdered body was found in a remote Wyoming forest, fancied himself as a cartoon-style illustrator.
His multiple works displayed on Instagram show an obsession with dark themes of death, spurting blood, violence and antihero characters.
But as Florida police and the FBI search for Laundrie after an autopsy confirmed 22-year-old Petito met with foul play, one of the juice salesman's designs could hint at what happened.
Petito's last known sighting was leaving a Utah hotel with Laundrie on August 24 and she spoke with her mother, Nichole Schmidt, the next day.
On August 27, Schmidt received an "odd" text from her daughter's phone about Gabby's grandfather Stan, which her family now believes was sent by Laundrie.
Exactly a year earlier — in what Instagram sleuths believe is a macabre clue that points to the day Petito died — Laundrie posted on his Instagram page @bizarre_design_ a linocut he had made of a princess with red blood spatter across her mouth and neck.
He added the cryptic comment: "Reading is different than any other consumption of media, it takes more effort than staring at a screen half alive, it allows you to use your brain rather than melt it."
But two days later, he posted linocut drawings of the cartoon characters Itchy and Scratchy, with the comment: "This was a fun one! I wanna give them little bodies with blood spraying from there necks, a lot of gore, maybe an axe or a chainsaw, generic Itchy and Scratchy stuff."
Another drawing shows a figure composed of blood spatter, with its hands reaching up in the air.
Instagram users have mercilessly mocked Laundrie on his page, saying his work is childish and derivative, or just straight-out copies of others work.
Laundrie's pen and ink drawings and linocuts include a drawing of two fighting figures, one of whom stands victorious with his club holding the other's head.
Laundrie's comment alongside is: "How man treats one another."
Another drawing depicts what he describes as "Grim Reaper leading sheep to the slaughter".
The artworks feature fictional characters from cartoons and movies like Hellboy and Predator, as well as demonic-looking figures.
Students from the Bayport Blue Point High School which both Laundrie and Petito attended — a grade apart, graduating respectively in 2016 and 2017 — remember him as a quiet kid who preferred art over sport.
"I don't remember ever seeing him be the aggressor in any situation. He almost always had a smile on his face whether it was in the classroom, lunch, hallways, etc," one person told bronx.news12.com.
Petito's body was found in a remote camping area in the Bridger-Teton National Forest this week, after being reported missing by her family on September 12.
An autopsy has confirm she likely died of homicide, although details about her exact cause of death have not been released.
Gabrielle "Gabby" Petito met Laundrie in the town of Bayport in New York State's Long Island.
They became engaged in July 2020 and the couple moved to his parents' North Port home. They set off to see the US's most iconic locations on July 2, 2021.
They travelled in a white 2012 Ford Transit van with Florida licence plates belonging to
Petito, who uploaded photos and videos on her Instagram page and blog posts about their travels.
The images showed a young couple kissing in spectacular locations and camping under the stars in America's great national parks.
But in texts and phone calls to her family, Petito made it clear there were tensions between the two.
These appeared to boil over in Moab County, Utah, where police pulled the pair over after a couple reported seeing a man slapping a young woman.
Brian Laundrie arrived home to his parents Florida home on September 1 without Gabby.
Ten days later, Petito's family reported her missing and Florida Police knocked on the door of Laundrie's parents' home.
Laundrie's parents, Roberta and Chris, via their lawyer refused police access to interview Brian.
On September 17, they reported to police that they had not seen him since September 14.
This week, an alleged sighting of Laundrie was made in the Florida panhandle region after a deer hunter found an image on his trail cam of man who resembled Brian Laundrie.
In the footage, which was taken in wilderness near the town of Baker in Okaloosa County, Florida, the man wears a backpack which social media observers claim matches Laundrie's.
However neither Okaloosa County sheriff's officers not police near Laundrie's family home in North Point Florida have been able to locate him.