Mr. Tillman, who was posthumously promoted to corporal and awarded the Silver Star for valor, inspired legions after he quit his spot as a star defensive back for the Arizona Cardinals professional football team to be an Army Ranger.

Image Former Pvt. Jessica Lynch leveled criticism today at the hearing about the initial accounts given by the Army of her capture in Iraq. Credit... Mark Wilson/Getty Images

The Army recently completed two inquiries into his death. The investigations found that even though soldiers and commanders suspected almost immediately after the death that it was accidental fratricide, Corporal Tillman’s family was not notified about the true circumstances until more than a month later, a violation of Army rules.

The report from the inspector general’s office in the Defense Department singled out four generals and five other officers for potential discipline but said that they had done nothing criminal and that there was no broader cover-up.

The report was especially critical, however, of Lt. Gen. Philip R. Kensinger Jr., head of the Army Special Operations Command at the time of Corporal Tillman’s death. The document said General Kensinger most likely knew of the suspected fratricide before a nationally televised memorial service on May 3 that he and the Tillman family attended.

The oversight committee had requested that General Kensinger testify on Tuesday, but he declined through a lawyer, citing his constitutional right to avoid compelled self-incrimination.

Committee members heard from Specialist Bryan O’Neal, who was with Corporal Tillman when he died. Specialist O’Neal said he knew immediately that it was American troops that had killed his comrade and that he wanted to tell Kevin Tillman, who was a specialist in the same platoon, right away. But he was barred from doing so, he said, by his battalion commander, Lt. Col. Jeff Bailey.

“I was ordered not to tell him what happened,” he said, explaining that it was made clear that he “would get in trouble.”