A California congressman wants Mattis to award the Medal of Honor to a Marine after years of controversy

Congressman Duncan Hunter is urging the new secretary of defense to re-examine the case of Sgt. Rafael Peralta, a Marine who died in house-to-house fighting during the 2004 Battle of Fallujah.

In a letter to Defense Secretary Jim Mattis, the Republican congressman wrote that it is his hope "that we can finally give Sergeant Peralta the recognition he deserves."

In 2008, the Marine Corps recommended Peralta for the Medal of Honor after fellow Marines told investigators the 25-year-old sergeant jumped on a grenade and shielded them from the blast after he was mortally wounded by insurgent fire. The recommendation went all the way up to Defense Secretary Robert Gates, who initially approved it, before rescinding the decision amid an inspector general's complaint.

An independent review panel later found that the grenade did not detonate beneath Peralta's body. Peralta's award was downgraded to the Navy Cross. And years later, in 2014, a number of witnesses came forward to The Washington Post to say they had embellished the original story.

Still, Hunter has been fighting for years to get the Pentagon to upgrade the award to the nation's highest honor. Two other defense secretaries, Leon Panetta and Chuck Hagel, declined to overturn Gates' ruling.

"Multiple eyewitnesses conveyed that from their respective fields of view, Peralta initiated several movements toward the grenade and pulled it into his body," Hunter wrote. "In the spirit and tradition of the Medal of Honor, these eyewitness accounts are exceedingly sufficient, but they were overridden based on questionable forensic evidence assembled by Pentagon bureaucrats."

Hunter is optimistic that Mattis, the former commander of 1st Marine Division, will look into the case. Hunter told the San Diego Union-Tribune Mattis had originally signed off on the Medal of Honor award recommendation before it went up to Gates.

"I believe you have the right perspective and familiarity with the facts to make an informed judgment on this matter," he wrote. "Even more so, you have the courage to do what's right where others have been too sensitive to internal Pentagon politics."

The public affairs office for the defense secretary did not immediately respond to a request for comment.