Special counsel Robert Mueller's investigation into the anthrax attacks following 9/11 -- one of the most important of his career -- did not go well, to say the least.

Mystery surrounds Robert Mueller and his investigation into Russia and President Trump. Some think he is the ultimate professional, others that he is a Democrat lackey, still others maintain he is working on Trump’s side.

We can see how he works if we look at how Mueller ran his second-most important investigation as FBI Director. In September of 2001, an entity began mailing anthrax through the US Postal system, hitting such prominent targets as NBC and Senator Daschle’s office. The terrorist attacks killed five and left others hospitalized. The world panicked.

Under Mueller’s management, the FBI launched an investigation lasting ten years. They now brag about spending “hundreds of thousands of investigator hours on this case.” Let’s take a closer look at Mueller’s response to understand the context of the investigation — who his people investigated, targeted, and found guilty.

The anthrax letters began just a week after the 9/11 attack. While planning the airplane hijackings, Al-Qaeda had been weaponizing anthrax, setting up a lab in Afghanistan manned by Yazid Sufaat, the same man who housed two of the 9/11 hijackers. Two hijackers later sought medical help due to conditions consistent with infection via anthrax: Al Haznawi went to the emergency room for a skin lesion which he claimed was from “bumping into a suitcase,” and ringleader Mohamed Atta needed medicine for “skin irritation.” A team of bioterrorism experts from Johns Hopkins confirmed that anthrax was the most likely cause of the lesion. Meanwhile, the 9/11 hijackers were also trying to obtain crop-dusting airplanes.

So how did Mueller’s investigative team handle the case?

Mueller issued a statement in October of 2001, while anthrax victims were still dying: the FBI had found “no direct link to organized terrorism.” The Johns Hopkins team of experts was mistaken, the FBI continued, Al Haznawi never had an anthrax infection. The crop-dusting airplanes they needed was possibly for a separate and unrelated anthrax attack.

A few weeks later, the FBI released a remarkable profile of the attacker. FBI experts eschewed analysis of the content of the letters, where it was written in bold block letters, “Death to America, Death to Israel, Allah is Great.” Instead, they focused on a “linguistic analysis,” stating that the letter’s writer was atypical in many respects and not “comfortable or practiced in writing in lower case lettering.” The FBI therefore concluded that it was likely a disgruntled American with bad personal skills.

The investigators hypothesized that the attacker was a lonely American who had wanted to kill people with anthrax for some undefined time period, but then became “mission oriented” following 9/11 and immediately prepared and mailed the deadly spores while pretending to be a Muslim.

Mueller’s FBI honed in on Steven Hatfill as the culprit — a “flag-waving” American, who had served in the Army, then dedicated himself to protecting America from bioterrorist threats by working in the United States Army Medical Research Institute of Infectious Diseases.

There was no direct link from Hatfill to the attacks, by the FBI’s own admission, and the bureau never charged Hatfill. The FBI did however spy on, follow, and harass him non-stop for years. The Department of Justice also publicly outed Hatfill as the possible terrorist.

While Hatfill’s dignity and life was being trampled on by America’s secret police, Mueller took a stand. But on a different topic. He made front page news for threatening President Bush he would resign over NSA policy. All while his own team was trampling on the rights of an American in the FBI’s largest-ever investigation.

Hatfill successfully sued the government for its unlawful actions. He won almost $6 million dollars.

After the Hatfill investigation blew up in the FBI’s face, they moved on to Bruce Ivins, another Army researcher who had actually volunteered to help the FBI investigate this case, and had been doing so for years. It wasn’t until five years after the attack that Mueller’s men decided Ivins was a target.

The FBI case against Ivins, once again, was based on circumstantial evidence.

The prosecution stated Ivins purposefully gave a misleading sample of anthrax spore, but Frontline documented this was not true. Ivins was “familiar” with the area from which the anthrax letters were mailed, the FBI said, but Pulitzer Prize winning ProPublica lays out the accepted facts of the case showing it was impossible for Ivins to make the trip to mail the letters.

The spores used in the attacks were a similar type to the laboratory spores where Ivins worked, but that ignored the fact that the anthrax letters had a unique additive — so sophisticated and dangerous a scientist commented, “This is not your mother’s anthrax” — that was likely produced by a nation state or Al-Qaeda.

Ivins was never indicted, just given the Hatfill treatment. His house was raided, and he was threatened with a death sentence, or as his lawyer put it, put under “relentless pressure of accusation and innuendo.” He committed suicide.

One week later, U.S. Attorney Jeffrey Taylor stated Ivins was guilty “beyond a reasonable doubt,” and they were “confident that Dr. Ivins was the only person responsible for these attacks.”

Democratic Sen. Patrick Leahy, one of the intended victims of the anthrax terror attacks, did not believe that Ivins was the sole actor. Mueller ordered an independent audit of the FBI’s case by the National Academy of Sciences, then formally closed the case in 2010, sticking with the conclusion that Ivins, and Ivins alone, committed the terror attack. One year later the NAS released their results and confirmed what many scientists had been repeating for years: the FBI’s science and conclusions were not solid.

A former FBI official involved in the investigation sued the FBI, alleging the FBI concealed evidence exculpatory to Ivins.

Mueller made his position known, saying, “I do not apologize for any aspect of this investigation,” and stated that the FBI had made no mistakes.

The investigation was an unmitigated disaster for America. Mueller didn’t go after al-Qaida for the anthrax letters because he couldn’t find a direct link. But then he targeted American citizens without showing a direct link. For his deeds, he had the second longest tenure as FBI Director ever, and was roundly applauded by nearly everyone (except Republican Rep. Louie Gohmert).

Now he’s running the Trump-Russia investigation.