We had the photos and fingerprints of other terrorists and that didn't stop them. These people are not here to get a job, and they are not here to commit petty crimes. They are here to blow themselves up, and they are not particularly concerned about whether they escape or not. Advocates of closed borders are beginning to sound more one-track than the leaglize drugs mafia. Not EVERY story is about your issue.
You're also forgetting that we are routinely turning potential terrorists away from flights because they're on watchlists. If I'm a betting man, and I'm a terrorist, I'm not gambling my name hasn't filtered through somewhere to the DHS and I'm getting kicked off a plane...
As for the mug shots, fingerprints, and what not, I suppose we'll have to let events work themselves out before passing final judgment.
The people smuggling, document forgery, and identity theft industries in this country are multi-billion dollar industries thanks to the illegal alien industry in this country. Tailor-made for terrorism. They are most certainly related. They exist (on such a scale) because of each other.