As the second unit's lead vehicle broke free of the canyon, Baker, who was standing in the front passenger side, spotted the dark-skinned Afghan soldier on his feet and firing an AK-47 in the direction of the convoy. He took aim.
Baker told ESPN.com that he didn't realize he had targeted a friendly Afghan soldier, one of four who a few days earlier had joined the Rangers for a sweep operation of the countryside, or that the Afghan was firing over the convoy, at an enemy position high atop the ridgeline.
Neither, Baker said, did he realize that just a few feet off the Afghan's right shoulder were two Americans in Ranger uniforms: Pat Tillman and O'Neal.
The Afghan was killed, his gut torn open as Baker let loose eight rounds.
Baker's first shots triggered wild, frenzied firing from the young shooters under his charge in the vehicle, engaging everything in the vicinity of the friendly Afghan.
"Well, we teach our guys to, you know -- one of our fire commands is to shoot where the leader shoots," Baker said to ESPN.com.
And that is what they did?
"Right," Baker answered.
But according to one of the Rangers in the first unit, the soldiers also are trained to make certain they know what they are aiming at before they pull the trigger.
"I was always taught: identify, acquire, engage," Arreola said in an interview with ESPN.com. "Identify your target. Acquire it -- put your gun sight on it. And if the threat is there, engage. So that is what I did. And that is why I shot up on top of the mountain, knowing that nobody we would give a s--- about is up there. And if anything, the threat is up there."
When asked by ESPN.com whether the Rangers in the second serial should have known what they were shooting, Arreola said: "Yes, definitely. That is what we are taught. It is burned into our minds."
Arreola, who was in the last vehicle of the second serial, told ESPN.com he did not shoot at Tillman or the other Rangers on the ridgeline. Both Arreola and Mansfield were interviewed on Memorial Day of this year at an Orange County, Calif., jail facility, where they are serving sentences for felony assault for their part in a November 2004 bar fight in Fullerton.
Pat Tillman and other Rangers on the ridgeline frantically waved their arms. Tillman set off a smoke grenade. At one point, the firing ceased briefly when the soldiers in the trailing serial lost sight of their targets as their vehicle rounded a curve. Thinking the firefight was over, Tillman and O'Neal stood to stretch their legs. According to O'Neal's interview transcript from the Army's November 2004 investigation, the two Rangers assumed the shooters had recognized the tragic error.
"So we figured we were fine," O'Neal recalled for investigators. "We figured it was -- you know, they realized we were friendly."
But the firing resumed.
This time, someone put three bullets in Tillman's head.