MEXICO CITY (AP) — Thieves killed two Australians and an American on a surfing trip to Mexico in order to steal their truck, particularly because they wanted the tires, authorities said Sunday.

Baja California state prosecutors released grisly details of the slayings, but have not yet officially confirmed the identification of the bodies. They said family members of the victims are viewing the bodies to see if they can be identified by sight.

The corpses were decomposing after the thieves dumped them into a remote well about 50 feet (15 meters) deep, some 4 miles (6 kilometers) from where the foreigners were killed. If relatives can’t identify the bodies, further tests will be conducted. The well also contained a fourth cadaver that had been there much longer.

“The probability that it’s them is very high,” said chief state prosecutor María Elena Andrade Ramírez, noting the corpses still appeared to be identifiable by sight. “If they say that they are not completely certain that it is their relative, we would then have to carry out genetic testing.”