Killer Instinct

Nov. 12 -- The 101st Airborne Division's Tiger Force was among the most elite units in the Vietnam War, tasked with cleaning out the enemy in a string of villages in the Central Highlands of Vietnam. But according to an Army investigation, which the government kept secret for almost three decades, the mission turned into a seven-month-long mass murder.

Between May and November 1967, the highly-decorated, all-volunteer reconnaissance unit, which was attached to the 101st Airborne, moved through a series of villages deep inside Vietnam's Central Highlands, territory controlled by the Viet Cong and their North Vietnamese allies. Their orders were to ambush and booby-trap enemy combatants, but the 45-strong unit took the war to the villagers, killing hundreds of them.

Medic Rion Causey, 55, who is now a nuclear engineer in California, says he watched as soldiers killed unarmed civilians. He estimates the unit killed 120 civilians in one five-week period alone.

"Murder was not uncommon," former Tiger Force Sgt. William Doyle, 70, told ABCNEWS, confirming what has now been revealed in Army documents. "It was more or less the rule of the day.

"We trusted absolutely nobody," he said. "You know, that was rule number one."

The Tiger Force investigation was kept secret by the Army for almost three decades until last month, when The Blade, a newspaper published in Toledo, Ohio, ran a four-part series on the killings and investigation that followed. The series was based on an eight-month investigation by reporters Mike Sallah, Mitch Weiss and Joe Mahr, who obtained hundreds of pages of classified Army documents.

"What they would essentially do is they would kill prisoners, they would kill soldiers, they would kill villagers and they would sever the ears to wear as necklaces," Sallah told ABCNEWS. "Twenty-seven Tiger Force soldiers testified during the Army's investigation that they had either taken part in the ritual or that they had witnessed it firsthand — the severing of ears to be made into necklaces."

The Army said today it is conducting a preliminary assessment of any new evidence raised by The Blade's reporting. The assessment will determine whether a new case will be opened, Army spokesman Lt. Col. Kevin Curry told ABCNEWS.