Evidence and proof are far different.

The evidence linking al Qaeda would be their obvious motive to use anthrax vs. the U.S. coupled with the fact that the attacks took place just around 9-11, their attack. Additional evidence includes their desire to specifically use anthrax and their attempts to acquire, use and test the substance, which was discovered in Afghanistan years ago.
Attempt to purchase: http://edition.cnn.com/2003/WORLD/asiapcf/southeast/10/10/alqaeda.anthrax
Further attempts to find anthrax: http://www.washingtonpost.com/wp-dyn/content/article/2006/10/30/AR2006103001250.html
Very interested in using anthrax per detainee admissions and documents show uncertainty over whether al Qaeda obtained anthrax though really wanted it: http://www.jamestown.org/terrorism/news/article.php?articleid=2369800

Evidence that hijackers may have conducted the attacks: http://www.edwardjayepstein.com/nether_WWDK7.htm

That is evidence, not proof, that al Qaeda was involved in the attacks. I’d still like to know for sure who did, just as you do but saying for certain that al Qaeda didn’t do it isn’t supported by ALL the evidence.

Further, there were some samples of the evidence which survived.

And then, there were survivors of the attacks.

And there were likely means and motives (not lone wolf).

In a stroke of absolute fortune, there are witnesses who would still like to talk with the FBI…however, they have not been interviewed.

On the downside: most of the early problems in the investigation stemmed from law enforcement responders, not microbiologist/epidemiologist responders being first-boots-on-the ground. The public health departments in affected areas were unprepared. AMI employees were allowed to reenter the building to remove personal effects, then later informed they had been re-exposed.There was no survivor’s support network, even though the US Department of Justice is supposed to provide an advocate for victims in such cases.

It was also incredibly fortunate that anthrax is not an ambiguous illness, and will trigger suspicion of even novice healthcare workers.

The bacterium smells awful. It can easily be seen with any microscope. The illness is treatable at present.

The FBI had the responsibility of handling the law enforcement aspect of the case. The haze occurred when there was no clear medical incident command established at various points.

During medical disasters now, emergency room physicians direct response and collaborate with public health officials. An enhanced surge capacity has been built since 2001. While not fully adequate, it is more likely to direct appropriate and timely response.

Mr. Hatfill offered up some non-kosher credentials. Boards of MQA nationwide have learned to deal decisively and immediately with bad paper.

The investigation is not cold. And since most people believe it is not a lone wolf serial killer at work, the investigation must identify who did what, and when.

Bob Stevens was something of an expert on al qaeda in South Florida. He had to be, as they were right around the corner from him at work. The evidence does not go away, so the investigation is not compromised. Upon more sophisticated examination, certain characteristics of the anthrax used and of its preparation point not-to it having come from anwhere, but from a certain group of somewheres.

There would have been no justification possible for mounting a war against a transnational terrorist group existing in many locales…by attacking one particular country…especially when the immediate need is for indentification of domestic terrorists. We are engaged in a terrorist conflict, not a conflict involving national identities and territories.