The Betrayal of Anne Frank: A Cold Case Investigation

A three-and-a-half-foot square print of an aerial photo of the Prinsengracht canal taken from an English RAF airplane on August 3, 1944, covered a large part of another wall. It had been shot just twelve hours prior to the arrest of the people in the Annex. In the photo you can clearly distinguish Otto Frank’s office and warehouse and the Annex behind it. The people in hiding were still inside. They had no idea that they were spending their last night in what passed for freedom. Thijs told me that looking at the map gave the team an uncanny sense of connection with the hiders, as if time were suspended.

Thijs’s partner, Pieter van Twisk, has the cragginess of all bibliophiles, which must come from their thoroughness and obsession with detail; you can be sure that any conclusions he reaches are backed up by proof. Like Thijs, Pieter found that the research the Cold Case Team had undertaken had turned out to be much more personal than he’d originally expected. In the early stages of the project, he was looking for information in the archives of the city of Groningen about a Dutch collaborator named Pieter Schaap. Toward the end of the war, Schaap had been in Groningen hunting down a resistance leader named Schalken. To Pieter the name Schalken sounded vaguely familiar.

Eventually he discovered a document in the Groningen Archives that acknowledged and registered people who had been in the resistance. It confirmed that Schalken had been one of the leaders of the National Fighting Squads (Landelijke Knokploegen; KP), the fighting arm of the resistance. It also indicated that he had been in hiding in the house of Pieter’s grandparents. He’d heard the story before in the family but had never taken it seriously.

The document he found listed the name of his grandfather Pieter van Twisk, after whom he’d been named, with text at the bottom of the page:


Was this risky and why? Yes, for the duration of his resistance career his was the contact address of the KP, the OD and the LO etc. Several prominent resistance fighters, among them Schalken, found shelter at the family house. The above-mentioned people were wanted by the SD. Earlier he was being useful in the hiding of weapons.1



Schalken was never caught, nor were Pieter’s grandparents arrested. Pieter remembered his uncle, who had been a young boy during the war, telling him that he’d looked up to Schalken. Once, during a Nazi raid, the man calmly walked out of the house, stopped, lit a cigarette, and, very relaxed, stepped onto his bike and rode off. None of the Nazi officers suspected that he was the one they were looking for.

Clearly, it’s hard to find a family in the Netherlands that does not have a story connecting it to the war.



In the decades after the war, the popular narrative was that most Dutch people had been against the Nazis and many people had been in or supported the resistance. During the postwar period, most European countries clung to this narrative, but reality was much less monochromatic. In the last thirty years, Pieter believes, a more nuanced picture has emerged about the Netherlands and the Holocaust, first among historians and now also among part of the population.

His is the country that gave birth to Baruch Spinoza, the philosopher of liberalism, and had a long history of tolerance that led many Jews to seek refuge there after Hitler’s rise to power in 1933. Anti-Semitism there was mild in comparison to that in many other European countries. Yet the Netherlands transported more Jews to their deaths in extermination camps in the east than any other country in Western Europe. Of the 140,000 Jews living in the Netherlands, 107,000 were deported and only 5,500 returned.

Pieter said that one of his motivations for joining the project was that he needed to understand why the numbers in the Netherlands were so high. Is racism like a pathogen in the human psyche and certain circumstances can activate it? In the Resistance Museum (Verzetsmuseum) in Amsterdam, the crudity of Nazi anti-Semitic propaganda was vicious and unrelenting. Posters of murderous “Jewish Bolsheviks” standing over bodies; a bloodied crucifix on the floor; grotesque caricatures of rapacious Jews in bowler hats and suits; terrifying images of Jews as subhuman cultural parasites. How could people believe such propaganda? By studying the society that Anne Frank lived in, Pieter hoped he might come to understand what had happened, the only way never to repeat it.

Having decided to launch an investigation into what led to the raid on the Annex, Thijs and Pieter searched for funding from a variety of sources, including crowdsourcing, the Municipality of Amsterdam, and private investors, as well as publishers. They then set out to build a team of Dutch investigators, historians, and researchers. These included Luc Gerrits, a former homicide detective; major crimes investigator Leo Simais, the head of the Cold Cases and Missing Persons Department of the National Police Corps; several retired detectives; and one investigator from the General Intelligence and Security Service (AIVD).

At the first meeting of the team, on June 30, 2016, Leo introduced the so-called FOT sessions: with your “feet on the table,” you start talking, brainstorming, analyzing. Where to start? Leo couldn’t have been clearer—with the suspected phone call that the betrayer made to the SD about Jews hiding in a warehouse at Prinsengracht 263. How probable was it that the phone call actually took place? In Amsterdam in 1944, were there any public phone booths left? Had the copper telephone lines not been turned into weaponry? Was the SD phone number publicly known? And so on.

In this preliminary stage of the investigation, it quickly became clear that the Amsterdam police force during the Nazi occupation had played a questionable role. Like every other official body in the Netherlands, the police had had to collaborate to a certain extent with the Nazis during the occupation, but it seemed that a number of them had gone further in helping the Nazis than was strictly necessary.

So Thijs suggested that it would be good to have an independent outsider, someone non-Dutch, on the team. He asked Luc if he could find an FBI agent to lead the cold case. Betrayal is a nonforensic crime, since there are no physical traces, and the Cold Case Team would need to work with cutting-edge methods of information gathering to make headway. Luc turned to Hans Smit, the head of the National Police Corps undercover branch, who had been trained by the FBI. Smit suggested that Thijs call an old colleague from the FBI undercover unit who had only recently retired. “He’s the guy you are looking for,” Smit said. “His name is Vince Pankoke.”

Soon Thijs and Pieter skyped with Vince, who was living in Florida. Both were impressed by the kind and clearly highly professional investigator, who said he was intrigued by the project.

After eight years as a police officer, Vince had spent twenty-seven years as a special agent with the FBI, working undercover on high-profile cases against Colombian drug traffickers.

He had also worked the case against Sky Capital, whose CEO, Ross Mandell, might be considered to be a bit like the fictional character Gordon Gekko in the movie Wall Street. To meet Vince, you would never suspect him of having such a past. He still seems to be living undercover, a mild, anonymous man in a guayabera shirt, until you discover his passion for dangerous motorcycle races or his thirst for new challenges.

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