Former top brass testifies in Tillman's death probe

A house hearing began this morning in Washington about the death of Army Ranger Pat Tillman.

Tillman was killed by friendly fire in Afghanistan in 2004.

Former Defense Secretary Donald Rumsfeld is among those who testified at today's hearing.

He  said he's always impressed upon the Department of Defense the importance of telling the truth.

Tillman's death was initially categorized as being from enemy fire.

Lawmakers at today's hearing will try to determine when investigators determined Tillman's death was from friendly fire and why that information was not released sooner.

Before joining the military, Tillman played for the NFL.