Disturbing information continues to surface in the death of Cpl. Pat Tillman, an Army Ranger who was killed on the battlefields of Afghanistan in 2004.

Tillman, who gave up his professional football career to join the Army after Sept. 11, 2001, was held up as an example of bravery in combat. It was later revealed that he was killed by his comrades in a friendly-fire accident, information officials had kept secret for more than a month after his death.

Now, new reports have surfaced in documents obtained by the Associated Press. Army doctors who examined Tillman's body disputed the cause of death. The M-16 gunshot wounds to Tillman's forehead, they said, were the result of shots fired at close range, a mere 10 yards away.

The documents also revealed that there was zero evidence of any enemy fire, and that Army attorneys sent each other congratulatory e-mails for avoiding criminal investigators.

The Pentagon says it is taking action, with a new round of punishment including the demotion of high-ranking officers.

What's unclear is how high up the chain of command this deception went.

To find out, Rep. Henry Waxman (D-Los Angeles), chairman of the House Committee on Oversight and Government Reform, is digging deeper. Congressional hearings this week are aimed at finding out who initiated the erroneous story and exactly what the White House knew.

These are key questions — it's time for the truth.

For her part, Mary Tillman, Cpl. Tillman's mother, has long suggested that her son might have been deliberately killed by his comrades; she is still looking for answers.

With the cooperation of the White House and the tenacity of Congress, let's hope these answers come quickly. Tillman's family — and the American public — deserves the truth.