It's too strong a coincidence that the picture of the smiling suspect who everyone though was not the real killer also happens to be a copycat. Maybe the cops circulated that picture after finding a guy to pin this on but I dunno, just seems too elaborate for the NYPD.
The delay, deny, depose engravings don't seem like they'd be written by someone with this dude's ideology but
Maybe he's had a come to jesus moment in the past 6 months?