It's a picture of the Las Vegas bomber's military ID. Supposedly the body was severely burned, so it's unlikely that a plastic ID card would survive with only some minor scorch marks in the corner.

He was also in the Army Special Forces, and part of their job is to teach illiterate foreign peasants how to make improvised explosive devices. I think it's unlikely he would have chosen fireworks and propane canisters if he was making a bomb.