(CNN) — Defense Secretary Chuck Hagel has become the third-straight Pentagon chief to decide against recommending a Medal of Honor for a Marine who died fighting in Iraq.
Circumstances surrounding Sgt. Rafael Peralta's final moments in Fallujah in 2004 have been controversial for years.
Supporters of the Peralta family and some in Congress led by Rep. Duncan Hunter, a California Republican, have advocated for the award posthumously.
They believe Peralta, severely wounded by gunfire, pulled a grenade under his body and shielded other Marines from the blast.
They contend he gave his life to save others, an essential element of the Medal of Honor---the nation's highest battlefield award.
But Hagel has joined his two immediate predecessors, Leon Panetta and Robert Gates, in ruling that medical and battlefield evidence does not rise to the necessary level of certainty.
"Secretary Hagel determined the totality of the evidence does not meet the proof beyond a reasonable doubt Medal of Honor standard," a Pentagon statement said, noting that he would not reopen the award nomination for Peralta.
"Three separate secretaries of defense have now examined the case, and each independently concluded the evidence does not support award of the Medal of Honor," the statement said.
In previous reviews, some medical evidence indicated Peralta's head wounds were so severe that he would have been killed instantly, ruling out any conscious effort to smother the grenade.
Peralta, 25, of San Diego, has been posthumously awarded the Navy Cross, the second-highest award.