Is special counsel Robert S. Mueller III, appointed in mid-May to lead the investigation into suspected ties between Donald Trump’s campaign and various shady (aren’t they all?) Russian officials, the choirboy that he’s being touted to be, or is he more akin to a modern-day Tomas de Torquemada, the Castilian Dominican friar who was the first Grand Inquisitor in the 15th Century Spanish Inquisition?

Given the rampant media partisanship since the election, one would think that Mueller’s appointment would lend credibility to the hunt for violations of law by candidate, now President Trump and his minions.

But I have known Mueller during key moments of his career as a federal prosecutor. My experience has taught me to approach whatever he does in the Trump investigation with a requisite degree of skepticism or, at the very least, extreme caution.

When Mueller was the acting United States Attorney in Boston, I was defense counsel in a federal criminal case in which a rather odd fellow contacted me to tell me that he had information that could assist my client. He asked to see me, and I agreed to meet. He walked into my office wearing a striking, flowing white gauze-like shirt and sat down across from me at the conference table. He was prepared, he said, to give me an affidavit to the effect that certain real estate owned by my client was purchased with lawful currency rather than, as Mueller’s office was claiming, the proceeds of illegal drug activities.

My secretary typed up the affidavit that the witness was going to sign. Just as he picked up the pen, he looked at me and said something like: “You know, all of this is actually false, but your client is an old friend of mine and I want to help him.” As I threw the putative witness out of my office, I noticed, under the flowing white shirt, a lump on his back – he was obviously wired and recording every word between us.

Years later I ran into Mueller, and I told him of my disappointment in being the target of a sting where there was no reason to think that I would knowingly present perjured evidence to a court. Mueller, half-apologetically, told me that he never really thought that I would suborn perjury, but that he had a duty to pursue the lead given to him. (That “lead,” of course, was provided by a fellow that we lawyers, among ourselves, would indelicately refer to as a “scumbag.”)

This experience made me realize that Mueller was capable of believing, at least preliminarily, any tale of criminal wrongdoing and acting upon it, despite the palpable bad character and obviously questionable motivations of his informants and witnesses. (The lesson was particularly vivid because Mueller and I overlapped at Princeton, he in the Class of 1966 and me graduating in 1964.)

Years later, my wariness toward Mueller was bolstered in an even more revelatory way. When he led the criminal division of the U.S. Department of Justice, I arranged in December 1990 to meet with him in Washington. I was then lead defense counsel for Dr. Jeffrey R. MacDonald, who had been convicted in federal court in North Carolina in 1979 of murdering his wife and two young children while stationed at Fort Bragg. Years after the trial, MacDonald (also at Princeton when Mueller and I were there) hired me and my colleagues to represent him and obtain a new trial based on shocking newly discovered evidence that demonstrated MacDonald had been framed in part by the connivance of military investigators and FBI agents. Over the years, MacDonald and his various lawyers and investigators had collected a large trove of such evidence.

The day of the meeting, I walked into the DOJ conference room, where around the table sat a phalanx of FBI agents. My three colleagues joined me. Mueller walked into the room, went to the head of the table, and opened the meeting with this admonition, reconstructed from my vivid and chilling memory: “Gentlemen: Criticism of the Bureau is a non-starter.” (Another lawyer attendee of the meeting remembered Mueller’s words slightly differently: “Prosecutorial misconduct is a non-starter.” Either version makes clear Mueller’s intent – he did not want to hear evidence that either the prosecutors or the FBI agents on the case misbehaved and framed an innocent man.)

Special counsel Mueller’s background indicates zealousness that we might expect in the Grand Inquisitor, not the choirboy.

Why Special Prosecutors Are A Bad Idea

The history of special counsels (called at different times either “independent counsel” or “special prosecutor”) is checkered and troubled, resulting in considerable Supreme Court litigation around the concept of a prosecutor acting outside of the normal DOJ chain of command.

The Supreme Court in 1988 approved, with a single dissent (Justice Antonin Scalia), the concept of an independent prosecutor. Still, all subsequent efforts to appoint such a prosecutor have led to enormous disagreements over whether justice was done. Consider Kenneth Starr’s obsessive four-year, $40-million pursuit of President Bill Clinton for having sex with a White House intern and then lying about it. Special Counsel Patrick J. Fitzgerald’s 2006 pursuit of I. Lewis “Scooter” Libby is not as infamous, but it should be. Fitzgerald indicted and a jury later convicted Libby, a top aide to Vice President Dick Cheney, for lying about leaking to the New York Times the covert identity of CIA officer Valerie Plame Wilson. Subsequent revelations that there were multiple leaks and that Wilson’s CIA identity was not a secret served to discredit Libby’s indictment. Libby’s sentence was commuted. Libby’s relatively speedy reinstatement into the bar is seen by many as evidence of his unfair conviction. Considered in tandem, the campaigns against Democrat Clinton and Republican Libby raise disturbing questions about the use of special or independent prosecutors.

Yet despite the constitutional issues, the most serious problem with a special counsel is that when a prosecutor is appointed to examine closely the lives and affairs of a pre-selected group of targets, that prosecutor is almost certain to stumble across multiple actions that might be deemed criminal under the sprawling and incredibly vague federal criminal code.

In Mueller’s case, one can have a very high degree of confidence that he will uncover alleged felonies within the ranks of the inner circle of the President’s men (there are very few women to investigate in this administration). This could well include Trump himself.

I described this phenomenon long before Trump began his improbable rise, in my 2009 book “Three Felonies a Day: How the Feds Target the Innocent” (Encounter Books, updated edition, 2011). I explained how federal “fraud” statutes were so vague that just about any action in the daily life of a typically busy professional might be squeezed into the elastic definition of some kind of federal felony. Harvard Law Professor (and, I should note, my former professor and subsequent longtime friend and colleague) Alan Dershowitz has beaten me to the punch, making the case in a raft of articles and on TV and radio that none of the evidence thus far leaked to or adduced by investigative reporters constitute federal crimes.

But Mueller’s demonstrated zeal and ample resources virtually assure that indictments will come, even in the absence of actual crimes rather than behavior that is simply “politics as usual”. If Mueller claims that Trump or members of his entourage committed crimes, it doesn’t mean that it’s necessarily so. We should take Mueller and his prosecutorial team with a grain of salt. But a grain of salt seems an outmoded concept in an age when both sides – Trump and his critics – seem impervious to inconvenient facts. The most appropriate slogan for all the combatants on both sides of the Trump wars (including, alas, the reporters and their editors) might well be: “Don’t confuse me with the facts; my mind is made up.”

Harvey Silverglate, a criminal defense and First Amendment lawyer and writer, is WGBH/News’ “Freedom Watch” columnist. He practices law in an “of counsel” capacity in the Boston law firm Zalkind Duncan & Bernstein LLP. He is the author, most recently, of Three Felonies a Day: How the Feds Target the Innocent (New York: Encounter Books, updated edition 2011). The author thanks his research assistant, Nathan McGuire, for his invaluable work on this series.