But, CBS News Correspondent Lara Logan reports, the Army knew the popular footballer had been killed by fellow Rangers during a patrol in Afghanistan, but did not inform his family and the public for weeks.
The Army even allowed an emotional memorial service to take place, with testimonials from soldiers involved in the firefight, reports Logan, who has covered the Afghan campaign from its early days and traveled with U.S. Special Forces.
At the service, Tillman was awarded a posthumous Silver Star, one of the military's most distinguished honors for gallantry on the battlefield.
A new Army report shows that Gen. John P. Abizaid, the theater commander in Afghanistan, and other top Army officials were aware an investigation had determined the death was caused by an act of "gross negligence" four days before a nationally televised memorial service, the Post reported after reviewing nearly 2,000 pages of documents it had obtained.
Tillman, 27, turned down a multimillion-dollar contract with the Arizona Cardinals to join the Army after the Sept. 11, 2001, terrorist attacks. He was taking cover behind a boulder along a canyon road near the Pakistani border when a firefight erupted at twilight on April 22, 2004.
Tillman's platoon had to split up because of a broken Humvee. When the second half of the platoon rounded a corner, they mistook Tillman, another Ranger and an Afghan soldier as the enemy.
The Post reported on its online edition Tuesday night that troops on the scene said they were immediately sure Tillman was killed by a barrage of American bullets.