Gabby Petito’s cause of death was strangulation, a coroner confirmed on Tuesday.
The Teton County Coroner Dr Brent Blue revealed the results of his autopsy at a press conference on Tuesday afternoon.
“In the of death in Gabrielle Venora Petito, we find the cause of death the cause is by strangulation and the manner is homicide,” Dr Blue said.
He said decomposition suggested the body had been outside for three to four weeks.
Dr Blue confirmed that Ms Petito was not pregnant.
The release of details of her death represent the most significant update in the investigation since her remains were discovered on 19 September on the edge of the Bridger-Teton National Forest.
Dr Blue said the delay in releasing the cause of death due to the exhaustive investigation by law enforcement agencies including the FBI.
Ms Petito’s family were notified of the results before the press conference.
Brian Laundrie and Ms Petito left Long Island, New York, on 2 July on a months-long cross-country van-life trip.
On 12 August, police were called to a violent argument between the couple in Moab, Utah.
Mr Laundrie flew home to Florida on 17 August, leaving Ms Petito on her own in Salt Lake City.
He returned on 23 August, and the couple were seen checking out of a hotel room the next day.
Ms Petito was last seen on 27 August, and FBI appealed for sightings of her between 27 and 30 August.
On 1 September, Mr Laundrie drove the couple’s van back to Florida.
She was reported missing on 11 September, sparking a nationwide manhunt.
Mr Laundrie has gone on the run from authorities, and is the subject of a massive nationwide manhunt.