An adult male German shepherd mix was tied to a car and then dragged 3 miles to its death early Wednesday morning at the Colorado National Monument near Grand Junction.

“This was an incredible act of cruelty done to a defenseless animal,” Joan Anzelmo, superintendent of the monument, told The Denver Post.

Anzelmo said Wednesday night that, thanks to tips, authorities have focused on a specific suspect and hoped to have him in custody soon. She said that, based on information they have received, officials believe the dog had been stolen.

Anzelmo said tracks left in the snow clearly show how the crime was committed: The dog initially walked, then ran and eventually was dragged when it couldn’t keep up with the vehicle. It was finally dumped after it died from the dragging.

She said the German shepherd mix was forced to run up one of the steepest hills at the monument. During the 3 miles, the dog had to run on about 2 inches of snow, around multiple switchbacks and sharp curves that gained more than 1,000 feet in elevation before the animal collapsed and died.

The dog was found by the chief of maintenance of the monument about 4:30 a.m., with a silver and blue synthetic rope around its neck. Anzelmo said the employee was very upset.

The superintendent said there is quite a bit of evidence, including the tire tracks of the vehicle.

Investigators think the incident occurred between 2 and 4 a.m.

Anzelmo said she was optimistic the culprit would be arrested. She said there is no chance the dragging was unintentional.

Marylou Randour, a staff psychologist for the Humane Society of the United States, said the person or persons who committed the act is a psychopath. “He is someone who has no compassion or empathy for any living creatures,” Randour said.

Randour added that the individual is extremely dangerous and a threat to human beings as well as animals.

“He may not have been angry at all,” she said of the individual. “He may have done it for kicks — to torture an animal in an elaborate and detailed way.”

Randour, who has studied animal abusers for years, said a recent study of 43,000 people found that those with drug problems and mental-health problems are most likely to engage in animal cruelty.