[leadpenny]

. . . could be a terrorist with links to Islamic terror groups

I would be convinced of this theory if other major metro areas were involved.

OTOH, this could be a rogue Cell.

[Skywalk]

Other areas ARE involved--Bali, Finland, Yemen, Philippines, Kashmir, and Kuwait have all seen strangely reminiscent forms of violence in the last couple of weeks. Throw in arrests in Italy, Asia, PersianGulf and here in the US and how can we know for sure how many other murders were prevented.

Not saying it IS AQ, just that one has to look at the broader picture.