Additionally, on Tuesday, Sept. 21, the Teton County Coroner's Office announced her manner of death was determined to be homicide.
"Teton County Coroner Dr. Brent Blue confirmed the remains are those of Gabrielle Venora Petito, date of birth March 19, 1999," the FBI stated in a press release. "Coroner Blue's initial determination for the manner of death is homicide. The cause of death remains pending final autopsy results."
The mystery surrounding Petito's disappearance garnered national attention when her fiancé, Brian Laundrie, returned home from a cross-country road trip they were taking across the western United States. Despite driving her campervan back to Florida, Petito was not with Laundrie when he arrived. The couple was documenting their travels on Instagram and YouTube.
Over the weekend, on Sept. 19, a search party found human remains near a campsite on the eastern edge of the national forest. At the time, the Denver Bureau of the FBI stated the deceased's appearance was "consistent with the description" of Petito.
In the hours after the search for Petito ended, her brother and father took to social media to honor their loved one. "I don't even know what to say," her brother, TJ Schmidt, wrote. "I'm at a total loss. My heart is shattered #justiceforgabby."
Her father, Joseph Petito, added in a separate post, "#gabbypetito she touched the world."
According to an unsealed search warrant for a hard drive found in their van, obtained by E! News on Sept. 20, Petito sent a text to her mother, Nicole Schmidt, on Aug. 27, the same day authorities said her phone ceased operating. The message was about her grandfather and read, "Can you help Stan, I just keep getting his voicemails and missed calls."
The search warrant states that Schmidt described the message as "odd," as Petito didn't refer to her grandfather by his first name. "The mother was concerned that something was wrong with her daughter," the documents state.
Petito's parents eventually filed a missing persons report on Saturday, Sept. 11, 10 days after her fiancé returned to his family's home in Florida.
Authorities have identified Laundrie as a person of interest in the case, however, his whereabouts are unknown. According to the North Port Police Department, Laundrie's family said they have not seen him since Sept. 14.
"We understand the community's frustration, we are frustrated too," the police said. "For six days, the North Port Police Department and the FBI have been pleading with the family to contact investigators regarding Brian's Fiancé Gabby Petito. Friday is the first time they have spoken with investigators in detail."
The statement continued, "It is important to note that while Brian is a person of interest in Gabby's disappearance, he is not wanted for a crime. We are not currently working a crime investigation. We are now working a multiple missing person investigations."
A lawyer for the Petito family later said in a statement, "All of Gabby's family want the world to know that Brian is not missing, he is hiding. Gabby is missing."
It's unclear what transpired during the course of their road trip, as police said Brian "has not made himself available to be interviewed by investigators or has provided any helpful details" on the advice of his family attorney.
That being said, police reports and social media videos have provided investigators with details on Petito's final days.
According to NBC News, Petito's own social media accounts, as well as communications with her family, revealed that she and Laundrie traveled through Utah, Colorado and Kansas, before ending up in Wyoming, where Petito was last seen.
It was during their travels in Utah that the couple had an encounter with local authorities. According to NBC News, two police officers responded to a report of a "domestic problem" between the pair on Aug. 12. One officer wrote in the report that Petito said she slapped Laundrie during an argument, prompting Laundrie to lock her out of their van. She eventually got into the vehicle.
When Petito and Laundrie spoke to police, they indicated that tensions were high because of mental health problems. The report read, "The time spent created emotional strain between them and increased the number of arguments."
After speaking to the couple, police said they recommended Petito and Laundrie spend the night apart from each other, with Petito maintaining custody of the van.
What followed their altercation is still unknown, though the discovery of Petito's remains offers authorities a new lead to investigate.
FBI Denver Special Agent in Charge Michael Schneider said on Sept. 21, "The FBI and our partners remain dedicated to ensuring anyone responsible for or complicit in Ms. Petito's death is held accountable for their actions. Mr. Brian Laundrie has been named a person of interest. Anyone with information concerning Mr. Laundrie's role in this matter or his current whereabouts should contact the FBI."