An assumption. Just like an assumption about white guys in a white van. Assumptions are dangerous things, they get people killed.
Actually my comment was somewhat "tongue in cheek" but you point about assumptions can actually go both ways.
At any rate, I'm not going to second guess the police work in this case or assume that it could or couldn't have been better. I will say that solving this unique case that didn't fit any previous patterns in 22 days sounds pretty good to me.
This unprecedented cooperation between departments (local, state & Federal) along with unlimited resources may have set a new standard.
Now, if I could feel as confident about our court system...
"Assumption.": Templar
Sounds more like genuine, good, old, deductive reasoning to me, as opposed to an assumption, Templar.
Try adding a couple of Sherlock Holmes crime mysteries to that impressive list of books you've read. That might better illustrate the difference between deduction and assumption for you.
For example:
The victims have several things in common.
1) They're all American.
2) They're all non-Arab.
3) They're all non-Muslim.
4) They're all regular, innocent folks just going about their average everyday business.
5) I believe it's been confirmed they were all killed at times-of-the-day other than Muslim prayer times for the Beltway area.
Another bit of pertinent information are the Al Qaida training tapes that were discovered by our soldiers in Afghanistan prior to May/2002.
New Al-Qaida training tape shows another side of terror
This tape contains detailed information on the use of a variety of vehicles as shooting platforms for snipers.
The point is the authorities had plenty of reason to believe that the snipers were Muslim terrorists. Especially, in light of the 9/11 tragedy and all of the threats Muslim terrorists have made against American citizens and American interests, since.
Sherlock Holmes would have called all of these pertinent details clues.
It's obvious that a lot of LE working on this case didn't have one, or had personal motivations or orders from higher authority to ignore them.
I hope the surviving family members sue the INS and everyone else on down that was involved in this fiasco.