Without knowing how they got into his phone, this is a non-story that is just a retelling of older stories. For all we know they just took his dead finger and put it on the reader. Or maybe he used the same 4-digit PIN for his debit card or lock box or something else that they were able to recover. Maybe some detective just just randomly entered the shooter's birthday, only to say "Hey sarge, you're never gonna believe this... first try!"
There's nothing useful that can be taken away from this story yet, until more details come out.