US Army Sgt. First Class Leroy Arthur Petry  is awarded the Medal of Honor for conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty by President Barack Obama at a White House ceremony on July 12, 2011.  (J.Lee / Staff)

ALTERNATE CROP OF WHCD102 - President Barack Obama shakes the prosthetic hand of U.S. Army Sgt. First Class Leroy Arthur Petry of Santa Fe, N.M., who received the Medal of Honor for his valor in Afghanistan in a ceremony in the East Room of the White House in Washington, Tuesday, July 12, 2011. Petry lost his right hand as he tossed aside a live grenade during a 2008 firefight in Afghanistan, sparing the lives of his fellow Army Rangers. (AP Photo/Charles Dharapak)

President Barack Obama shakes the prosthetic hand of U.S. Army Sgt. First Class Leroy Arthur Petry of Santa Fe, N.M., who received the Medal of Honor for his valor in Afghanistan in a ceremony in the East Room of the White House in Washington, Tuesday, July 12, 2011. Petry lost his right hand as he tossed aside a live grenade during a 2008 firefight in Afghanistan, sparing the lives of his fellow Army Rangers. (AP Photo/Charles Dharapak)