California ? The mother of a Marine who witnesses say covered a grenade with his body to save comrades in Iraq plans to appeal to Congress to award her son the nation’s highest military honor after learning it was denied by Defense Secretary Robert Gates because of questions about his final act.

Rosa Peralta said Thursday she made the decision after a Marine general told her that her son, Sgt. Rafael Peralta, would be awarded the Navy Cross rather than the Medal of Honor because the nomination was tainted by reports he was accidentally shot by a fellow Marine shortly before an insurgent lobbed the grenade.

“I’m going to see what can be done, because I’m not satisfied with what they want to do now,” she said in Spanish.

The question about whether to award Peralta the Medal of Honor centers on whether the mortally wounded Marine, who was shot in the head and upper body, could have intentionally reached for the grenade and covered it with his body.