53 pictures and one video is what was on his phone, he's charged with 64 counts, so they found more elsewhere, but it also says there were other files that were corrupted or incomplete. And they also seem to indicate some of those charges are related to programs and identifying files, so like their history probably.
The thing is, they can essentially only charge him with the files that they were able to download off of him if they want to hit him with the biggest charges. I'm assuming the phone is an easier case to say he put them there. (Unless GAF did obviously.) But in terms of proving evidence, and this applies in lots of torrenting/p2p/etc. cases, the state won't charge except on the ones they can prove you were sharing on their end. Because it's otherwise easily a case of he said/she said. He can say "I didn't put those there" or "I lent it to these dudes across the hall and they put it there before leaving and stealing my Xbox" or whatever and it's not good enough to say "we think you did" to where they'll prosecute.
Now, where he really fucked up, is in admitting to it. To the point of trying to explain it away and claiming that he didn't know it was illegal.
All that forum swagger against Trump (he has posts about wanting him to die, etc.) and taking violent action against grotesque monsters worse than ISIS and shit, the instant the cops show up at his place he falls back on "I didn't know it was illegal" and "but but I have fetishes."
I hope the important ones of you are better criminals than this. Or this forum needs an enema.