Mary Tillman, mother of Pat Tillman, who died seven years ago, said McChrystal was unfit be a co-chairman of a commission on military families, a post to which he was appointed by President Obama this week, ABC News reported Thursday.
"I was actually pretty shocked to hear it; I don't think it's the appropriate choice," Tillman said. "Considering that we have plenty of evidence indicating that McChrystal was involved in the cover-up of Pat's death. ... [He's] not the right person for that kind of a job."
Tillman said McChrystal was part of an effort pushing the false story that her was killed by the enemy and hiding the truth.
"Someone who has a heartfelt desire to help families would not have been involved in the cover-up of a soldier's death, especially one that they used to promote a war," she said.
McChrystal was the commander of special operations in Afghanistan when Tillman died in April 2004. Even as he was stating publicly that Tillman was shot by the enemy, McChrystal wrote his commanders that, "It is highly possible that Corporal Tillman was killed by friendly fire." He perpetrated the story for years, the family said.
The Pentagon Inspector General recommended disciplinary action against McChrystal, but the Army cleared him of wrongdoing in 2007.
He declined ABC News's request for comment.
"He deliberately helped cover up Pat's death and he has never adequately apologized to us for doing that," Tillman told ABC News.
Obama relieved McChrystal of command last summer after a Rolling Stone magazine story included degrading comments made by McChrystal and aides about the administration.