[Prodigal Son]

Last 2 paragraphs of article:

Although Atta is believed to have been resident in Florida in the summer of 2001, he is known to have used more than a dozen aliases, and intelligence experts believe he could easily have slipped out of the US to visit Iraq.

Abu Nidal, who was responsible for the failed assassination of the Israeli ambassador to London in 1982, was based in Baghdad for more than two decades.

[piasa]

Atta entered the US twice on the same day back in 2001, according to customs.