Teton County Coroner Dr. Brent Blue had previously ruled Petito's death a homicide, and though the cause was revealed Tuesday, he declined to provide details about Petito's autopsy or a potential suspect, saying he was limited in what information he could legally release.
Who killed Petito, when she was killed and what happened leading up to her death remain a mystery.
Even though there are more than 90,000 active missing person cases in the US, few met with as much urgency and national attention as that of Petito, who was reported missing in September 11 and whose remains were found more than a week later in Wyoming's Bridger-Teton National Forest.
Authorities are still searching for her fiancé, Brian Laundrie, who returned to Florida without her after their trip across the Western US.
Bad news for Brian Laundrie
A legal document Blue filed on October 5 with the Teton County Clerk of District Court specified that the cause of death was "manual strangulation/throttling."
"We believe this was strangling by a human being," he told CNN.
Blue declined to answer when asked if he suspects Laundrie is responsible for Petito's homicide, but ABC News Chief Legal Analyst Dan Abrams said the results could spell out bad news for Laundrie, who has been named by investigators as a person of interest in her death.
"When you're talking about strangulation, that is very typically the cause of death in domestic violence cases. It is angry. It is violent. It takes time. That is precisely what many believe happened here," he said.
Blue said Petito's body was left in the wilderness for three to four weeks before being found, but uncertainty remains about the exact date of her death.
"That was precisely around the same time that Gabby was last seen alive," Abrams said.
The autopsy of Petito's remains included a whole-body CT scan, an examination by a forensic pathologist and by a forensic anthropologist, and a toxicology analysis, Blue said at the news conference Tuesday.
The time since her death and the weather conditions she was subjected to make it harder to pinpoint an exact date of her death, Blue said.
"There will not be an exact date of death on the death certificate," the coroner added.
The autopsy has revealed more information than was released but will be held back due to the ongoing investigation, Blue said. He said Petito was not pregnant at the time of her death.
Blue said working on the case was "quite the media circus and continues to be." In addition to disappearance and death, the case has sparked conversations around domestic violence due to the release of body camera footage of an interaction between Petito, Laundrie and the police over one of the couple's fights.
"Unfortunately, this is only one of many deaths around the country, of people who are involved in domestic violence," Blue said. "And it's unfortunate that these other deaths did not get as much coverage as this one."
Mysterious text messages and a police call
The couple had spent the summer traveling in a white van and documenting their adventures on social media. But Laundrie returned to the Florida home they shared with his parents on September 1 without Petito, and her family was unable to get in touch with her.
She was first reported missing by her parents on September 11, and after an extensive search, her remains were found September 19 near where their van was last seen three weeks earlier. The national focus on her whereabouts revealed they were involved in a domestic dispute in Utah in August.
From the posts on social media, Petito's final days looked idyllic. But after she was reported missing, accounts surfaced of rising conflict between the couple.
WATCH: Tracking the Gabby Petito disappearance
The video above is a part of TRACKING, a digital video series from ABC News that uses social media, public records, mapping and expert analysis to piece together timelines of how major news events transpired. Watch more ABC News originals here.
Petito called her mom regularly, and those conversations appeared to reveal there was "more and more tension" in Petito's relationship, according to a police affidavit for a search warrant of an external hard drive found in the couple's van.
On August 27, an "odd text" from Petito worried her mother that something was wrong, according to a search warrant.
"Can you help Stan, I just keep getting his voicemails and missed calls," the message read, according to the affidavit. Stan was a reference to Petito's grandfather, who her mother said Petito never referred to that way, according to the affidavit.
Along their travels, the couple was stopped by police after a 911 caller told dispatchers August 12 he saw a man hitting a woman, according to audio provided by the Grand County Sheriff's Office in Moab, Utah.
"We drove by and the gentleman was slapping the girl," the caller said. "Then we stopped. They ran up and down the sidewalk. He proceeded to hit her, hopped in the car and they drove off."
CNN obtained dispatch audio recordings from the Grand County Sheriff's office last month that shed more light on what Moab police were told about "some sort of altercation."
And on August 27, a witness described a "commotion" as they were leaving the Merry Piglets Tex-Mex restaurant in Jackson, Wyoming.
Petito was in tears and Laundrie was visibly angry, going into and out of the restaurant several times, showing anger toward the staff around the hostess stand, the witness Nina Angelo said.
Angelo told CNN she did not see any violence or physical altercation between Petito and Laundrie.
The search for Laundrie
Before he disappeared, police in North Port were surveilling Laundrie as best they legally could, a police spokesperson told CNN's Randi Kaye.
Investigators said Laundrie's parents told them on September 17 he had left home days earlier and was headed to the nearby Carlton Reserve -- sparking a search of the nature reserve's 25,000 acres. Initially, his parents said he left on September 14, but last week, Laundrie family attorney Steven Bertolino said, "We now believe the day Brian left to hike in the preserve was Monday, September 13."
When he left, he didn't take his cell phone and wallet with him, and his parents were concerned he might hurt himself, a source close to Laundrie's family told CNN's Chris Cuomo.
He was later indicted on charges of allegedly using two financial accounts that did not belong to him in the days following her death.
In a statement Tuesday, Laundrie's family attorney Steve Bertolino said Laundrie had used a debit card that belonged to Petito but noted he was not a suspect in her death.
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