In their field of endeavor --- this "sport" of scaring the heck out of people --- they would have been following the "all-stars" in the game.
Osama bin Laden would have been one of the top "free agents" --- his "trading card" among the most desired at wherever terrorist cogniti gather to swap hints of their powers.
Wherever such vanity was served.
In the specialty area of bio-whatever, vanity is served quite well "at university" and in other government "research centers." There, are the laboratories and seemingly endless flow of cash from Congressional patrons, with which experimentation enthralls the acolytes.
Also there, are foreign students on visas which apparently could be purchased at any U.S. State Dept. vending machine in, to name one such franchise, the middle-Eastern Kingdom of Arabia.
So it seems that whether a fan of Osama's or a fan of the "sport," the fan adheres to a rarified atmosphere ... while the public does not go nor usually follow it in such minute detail.
That is to say, the perp is a long-time student of terrorism.
Yet the American powers that be, who are investigating, are shackled by the higher-ups' conditions (ie. the Bush [still running 75% of the Clinton] Administration):
Suspects who would reflect badly upon their having thrived with Congressional largesse are immune from prosecution.Suspects who have political ties to the Democrat National Committee are immune from prosecution. ("The politics of personal ... blah ... blah ... blah ... " immunity clause.)
Suspects who have political ties to areas of the issues about which the President has compromised, are immune from prosecution. (Such as anybody who spreads around Lynx fur "without criminal intent.")
Suspects who have international ties to foreign powers with whom the President has compromised, are immune from prosecution. (Exceptions: 1st, if the suspect is from North Korea to whom we are giving nuclear power, no prosecution; but 2nd, if the suspect is somehow from Iraq, from whom we are apparently going to try and take nuclear power, then skewer the S.O.B.!)
And so, given the above, by all means, go get somebody else --- find and publicly smear the "Center Wing Tank" and make the most of it.
Notwithstanding the initiating event(s).
To wit: If the perp is a guy named Mohammed, who is a cousin of the House of Saud with whom President Bush will not ruffle ... do not expect satisfaction.
Or: If the perp is a guy who is a cousin of the House Democratic Caucus with whom President Bush will not ruffle ... do not expect satisfaction.
Etc. Etc. Etc.
A very good question. Another possibility: The perp is psychotic, and the choice was based on something he/she saw in the checkout line that day.