Defense Secretary Leon Panetta is standing by his decision not to upgrade the fallen Sgt. Rafael Peralta’s Navy Cross award to a Medal of Honor after new evidence submitted by Rep. Duncan Hunter, R-Calif., apparently didn’t provide enough new information.

Peralta was killed on Nov. 15, 2004, in Fallujah, Iraq after jumping onto a grenade to save his fellow Marines during a house-clearing operation, according to Marine Corps News.

The Marine Corps nominated Peralta for the highest medal in the past, but it was resisted by then-Defense Secretary Robert Gates in 2008. Gates ruled the evidence was inconclusive, something that in Panetta’s opinion remains unchanged even after Hunter earlier this year submitted a pathology report and a video recorded moments before Peralta dove onto the grenade.

“Though eyewitness accounts are mostly (but not entirely) consistent, there is considerable medical and professional doubt about whether Sgt. Peralta could have performed the actions attributed to him, and whether the grenade exploded under him, as some suggested,” Panetta said in his letter, according to the Marine Corps News. “The doubts about this come from, among others, the Armed Forces Medical Examiner and his Armed Forces Medical Examiner System’s board of certified pathologists, and a number of other medical professionals who have looked at the case.”

Fox News reported that witnesses said Peralta was shot by friendly fire during the battle at Fallujah and quickly grabbed a grenade thrown into the area and placed it under his body, saving the unit from suffering further casualties.

When confronted with the case in 2008, Gates ruled that Peralta was unconscious when the explosive found its way under his body. Hunter has claimed the new forensic report proved the Marine knew what he was doing, although Panetta apparently remains unconvinced.

Navy Secretary Ray Mabus recently said he felt the medal should be upgraded in view of the pathology report. (The Marines fall under the Navy.) Hunter accused Panetta of using “arguments of convenience” in the case.

“For the first and only time on record, Secretary Gates formed a scientific panel consisting of several forensic experts to refute the findings and recommendation of both the Marine Corps and the Navy,” Hunter said. “Until then, there was absolutely no disagreement that Sergeant Peralta’s actions were in the spirit and tradition of the Medal of Honor. Secretary Gates manufactured the doubt — the same doubt that let Secretary Panetta not to award the Medal of Honor.”