Once charged as an adult, he will likely be identified, but the way juvenile law is normally written, the offender and victims if juvenile are concealed.

Once prosecuted, if the sentence spans both juvenile and adult time, the offender is transferred from juvenile detention to prison.

Personally I think that there’s a lot more going on behind the scenes, tracking him online, forums/videos watched, etc.
They don’t want to tip their hand while backtracking and allow someone to erase anything.