David Howard’s Chasing Phil tells the story of two young FBI agents who go undercover in the 1970s to expose a relatively minor con and get taken in, in every sense, by one of the great grifters of the last century, a master of multi-million-dollar scams involving multiple offshore banks—some of them legit, some of them shells—and a collection of accomplices around the world.

Back then, the bureaucrats at tbe Federal Bureau of Investigation headquarters in D.C., just recently free of J. Edgar Hoover, but still in his mold, really didn’t like this kind of undercover operation. They wanted to nail commies and Dillingers, not guys in suits with global connections in high finance. But the young agents, who to their amazement were accepted as apprentice con-men, kept jumping on planes to Hawaii, Hong Kong, the Bahamas and Frankfurt with their new buddy Phil Kitzer. Eventually, they were having a ball, and they might well have wondered where their loyalties lay (althought they insisted they always knew).

As Chasing Phil sketches the multiple layers of fraud in multi-million-dollar cons and describes the personality of Phil Kitzer, the central scam artist, one can’t help but think of another man who still likes to brag about “the art of the deal”:

“Phil was hard to read, partly because he was a skilled, habitual liar. He lied to con his marks, of course, but in the past seven weeks they’d watched him fib to just about everyone else—including them. … If he didn’t want to go outside, he would say that it was raining [even if it wasn’t]. He routinely offered letters of credit for 10 percent of face value, and after a client agreed, he would say he’d calculated wrong and jack the price up another few thousand dollars. One of his mottos was, Don’t tell the truth if you can avoid it.”

But Kitzer had a lot more class and a lot more charm than Donald Trump, and to the extent there is a link between the two, it is the fact that without Kitzer and the agents pursuing him, the FBI would have taken a lot longer to develop the expertise in fraud and finance that now is central to the Trump investigations headed by Robert Mueller, a former FBI director.

Operation Fountain Pen, as the Kitzer investigation became known, “cracked open a window into a world of financial crime the bureau had not previously understood or even glimpsed,” writes Howard.

Although it’s hard to imagine now, “for most of its history, the FBI had avoided undercover investigations” after Hoover watched Congress and the judiciary rebuke the bureau for such practices in the 1920s. “We do not question the right of the Department of Justice to use its agents in the Bureau of Investigation to ascertain when the law is being violated,” wrote a panel of prominent jurists. “But the American people have never tolerated the use of undercover provocative agents or ‘agents provocateurs’ such as have been familiar in old Russia or Spain.”

There was also the worry that undercover work would, in the words of criminologist James Q. Wilson, “expose agents to temptations involving money and valuable narcotics, [and] it would also require them to engage in enforcement policies that, though legal, struck many citizens as unsavory.”

As it happened, agents Jack Brennan and Jim “J.J.” Wedick were exposed to about every temptation imaginable, and they were an odd couple to begin with.

Brennan was a fourth generation Fed. His grandfather had played a part hunting down Pretty Boy Floyd in the epic era of gangsterism. Brennan’s father had taken the family to Alabama when he was investigating horrific violence against blacks and civil rights workers. Jack had spent some time outside the family business, making money in commodities trading, but finally found that pork belly futures were not his thing, and at 30 realized that the FBI might allow him a little more of the quality time with his wife and children that he wanted.

Wedick was driven, obsessive, intense and charming, 26 years old and working 16-hour days hunting down bad guys, unmarried and unconnected, relating as easily with his informants as with anyone else.

And then there was Kitzer himself, already a legend in the world of big-time con artists, but so hot for deals that he’d operate everywhere from the beaches of Hawaii and the Bahamas and the luxury hotels of Europe to the Thunderbird Motel in suburban Minneapolis, which is where Brennan and Wedick first met him in 1977 with their clumsily concealed little reel-to-reel tape recorder.

“Christ,” said Kitzer on that first encounter, “You guys look like a couple of Feds.” But he didn’t spot the recorder, and he liked them, and he decided he was willing to take a chance on them as apprentice front men. At the time Kitzer’s own profile had gotten a little too high, even in the pre-Internet world when bona fides were harder to check than they are now.

Within months, to the utter consternation of their gumshoe bosses, the two young Feds were flying literally around the world, sitting in on Kitzer’s scams and meeting some of the other great con men of the century, including Fred Pro who had once swindled Elvis Presley out of a private jet.

But Kitzer remained their main man, their mentor, their friend, and eventually their collar.

Born in 1933, Kitzer dropped out of school in 10th grade to go to work in his father’s bail bond business. After a stint as a draftee in the U.S. Army, he started a business selling insurance, figuring out the many potential scams in that business. By the time he was in his mid-twenties Phil and his father were under investigation in Chicago for the suspicious circumstances under which they wrote more than half of all the bonds posted in federal court. Among their clients, the infamous Teamster boss Jimmy Hoffa.

Kitzer realized that bail bonds, insurance, banking—these were systems that “could be manipulated behind the scenes, that people who managed to seize the controls of a business ought to pull the levers for their own gain.”

By the early 1960s, Kitzer and his relatives had created an insurance company that bought other failing insurance companies and “within a few years, they controlled a spider web of 15 businesses: eight insurance companies in Illinois, six in Minnesota, and a reinsurance firm across the Atlantic in London. They employed 25,000 brokers and took in many millions in premiums.” But Kitzer understood that as his business grew, so did the potential liability, so he kept creating and buying other companies to spread out the risk even as he started to pull out cash, using a real estate company the Kitzers established to launder the money.

“The scam was simple: Acquire an unwanted piece of property and pay someone to inflate its value.” Then the property would be assigned to the Kitzer realty company, which would withdraw the equivalent of the overestimated value in cash. It’s “a classic con man’s ploy also known as asset substitution,” Howard tells us, and “on the books, it looks like an even swap.”

By 1967, the Kitzers’ insurance company collapsed and it looked like the law had caught up with them. They went on trial in federal court in Bismarck, North Dakota. The case involved “bribery, blackmail, payoffs and corruption,” the U.S. attorney declared. It was a pyramid scheme with one insolvent company propping up another. “They stole, they gypped, they plundered, they took,” said the prosecutor.

Several young women were called to testify that Kitzer had invited them on trips to Florida, Puerto Rico, and Mexico. And the government’s key expert witness from the Treasury Department spent 50 hours on the stand walking the jury through what Howard calls “the dense thicket of Kitzer companies and transactions.”

But the Kitzers set out to confuse people even more, and in the end they walked.

“Kitzer picked up two lessons from his battle with the government,” Howard concludes. “Confusion is useful. Sleight of hand works. But mostly what he absorbed was that given the chance to tell his story, he could win over the regular folks in the jury box.

“In the end, he was the one they believed.”

By the time Wedick and Brennan met Kitzer almost a decade later, he had refined his techniques and expanded his contacts far beyond the American Midwest. In Europe he’d been hired as an international loan consultant for the United Nations, working under Kurt Waldheim. Howard reports that Kitzer “once arranged for Israel to obtain funding to purchase jets from the Nixon administration.”

But mainly Kitzer went about identifying vulnerable people, some of them quite powerful, who had run up massive multi-million-dollar debts in real estate and other businesses. He offered them the chance of salvation with loan guarantees backed by paper from real banks that Kitzer bought precisely to fail and fold, so that eventually he could pocket the money put down by his targets.

“The magic was in creating the illusion of assets, and in this regard Kitzer’s mastery of banking and insurance was invaluable,” Howard writes. Or, as Kitzer himself put it, “I have the capability of putting together deals and making people believe something that is not there.”

Young Wedick and Brennan were fascinated by Kitzer’s “alchemy of need and desperation and salesmanship” and within weeks had fallen into what Howard describes as their “both-ends-of-the-candle routine,” living the good life with Kitzer while collecting the evidence that eventually would put him and dozens of other high-profile fraudsters in jail.

Of course, that did happen eventually. And, as part of a plea bargain, Kitzer served just three years in prison, eventually lecturing at FBI offices, and helping to catch other bad guys who may have been worse than him. Over the years, although the FBI agents had betrayed him, they formed what they saw as an unbreakable bond of friendship.

Kitzer died in 2001, and after reading Chasing Phil one learns of his demise with more than a touch of regret. What might he tell us about the art of the deals that made our businessman-president’s fortune and put him in office? We’ll have to depend on the FBI agents and their successors that Kitzer lectured, instructed, and inspired to get that job done.