The cause of death Gabby Petito was strangulation and the manner of death was homicide, a Wyoming coroner announced Tuesday.
The announcement was made by Teton County Coroner Dr. Brent Blue at a news conference.
Officials also said her body was in he wilderness for three or weeks before being discovered.
Petito had spent the summer traveling through the West with fiancé Brian Laundrie, and documenting their travels on social media. But Laundrie returned to the Florida home last month the couple was shared with his parents Petito wasn't with him, according to CNN.
He reportedly used her debit card at some point late in the trip.
Laundrie has since gone missing, after purportedly going on a hike in a Florida nature reserve, with authorities looking for him to answer questions about what might have happened.
Laundrie's parents have given authorities conflict reports of when he left for the hike, first Sept. 14, then Sept. 13, CNN also reports.
The FBI searched the Laundrie home on Sept. 20, removing a number of items and towing away a Ford Mustang convertible.
After more than a week of searching for Laundrie, the FBI went back to his parents, asking for personal items of his to assist with DNA matching. They provided what they could, the Laundries' lawyer told multiple news outlets.