Quote from IShopAtPublix:
I would not put much stock into the time stamp. It could mean the initial prepare date and not count any amendments. They would not come to his father with pictures if they knew 100% who he was. Nor would they label him as john doe int he morgue. Reuters article I linked has a nice description of it where it says "Treyvon Martin as John Doe"
Trust me if you ever had a close family member if who has been a victim of a murder the police will show up with photos even if they know the identification of the victim. The pictures are used to confirm that the relatives corroborate the identification found in the wallet id.