An autopsy has revealed that Gabby Petito was killed by strangulation, according to the Teton County, Wyoming, coroner.

In a press conference on Tuesday, Dr. Brent Blue said the 22-year-old woman's death was ruled a homicide by strangulation.

Dr. Blue said he estimates Petito died three to four weeks before her body was located.

Petito's body was found in a Wyoming national forest after she was reported missing by her family September 11.

Her body was located Sept. 19 in the Spread Creek Dispersed Camping Area of the Bridger-Teton National Forest.

The last reported person to see her alive was her fiance Brian Laundrie, who authorities have named a person of interest.

Laundrie returned home to North Port, FL from the couple's cross country trip on Sept. 1 without Petito. Days after she was reported missing on Sept. 11, Laundrie was reported missing by his family after they say he went on a hike at the Carlton Reserve, but never returned home.

The search for Laundrie has been going on for more than three weeks with multiple reported sightings of Laundrie, but he has yet to be brought into custody of law enforcement.