Wolves in Alaska are suspected of killing a teacher in an isolated village while she was out jogging.
An autopsy has revealed that Candice Berner, 32, died of injuries sustained in an animal attack, officials said.
Her body was dragged off a rural road, leaving a bloody track, into the nearby bush and was surrounded by wolf tracks.
Police said wolves in the area had been aggressive recently. If confirmed, it is believed to be the first fatal wolf attack in the US in 50 years.
The Alaska State Medical Examiner said Ms Berner's cause of death was "multiple injuries due to animal mauling".
Col Audie Holloway, of the Alaska State Troopers, said: "There's no other carnivores in that area that are out and active.
"There were wolf tracks all around the body, and drag marks associated with those tracks."
Ms Berner had moved to Alaska from Slippery Rock, Pennsylvania, in August to work as a special needs teacher in the small community of Chignik Lake, about 474 miles (760km) south of Anchorage.
She had been training for long-distance running, a regional school official said.