I have not read anything about this, nor looked for any clues. That said, my first instinct with all of these events, like Charlie Hebdo, Nice, Boston Marathon, London 7/7, Sandy Hook (which the erstwhile Abby Martin dissed all who questioned the official narrative), etc, is that this is a scam.
Like I said, I have no reason apart from utterly cynical skepticism, to disbelieve the official story. However, anything that can be used to disarm the population or clamp down on personal freedoms, should, IMHO, be questioned very, very carefully.