I've been following since it was first posted and, for some reason, this thought just popped into my head.
What if this was a test/training run for something more nefarious? The fact that he had a change of clothing, somewhat hid his identity, potentially provided LE with false tips/ID of the perp and (finally) seemed to be running surveillance on the investigation. All of this, to me, suggests a highly organized, intelligent individual, with some type of background such an law enforcement, military, etc.
Was the perp testing his ability to commit a violent act, evade LE and leave the country and, if successful, plan a much more devastating (mass casualty) attack in the future?