Alan Prendergast is the author of “The Poison Tree” and “Gangbuster.” His work has appeared in Rolling Stone, Outside, the Los Angeles Times, 60 Minutes, Westword, and other publications, as well as The Best American Sports Writing and The Best American Crime Reporting. He lives in Denver.

SunLit: You’ve written extensively over the years about Colorado’s criminal justice system. What inspired you to choose Philip Sidney Van Cise as a book project? 

Alan Prendergast: I first became interested in Van Cise 15 years ago, when his family launched a public campaign to try to get some portion of the new Denver justice center named after him. Here was this innovative crime fighter from the 1920s, a pioneer in the use of electronic surveillance and a key figure in rescuing Colorado from the grip of the Ku Klux Klan — and yet very little had been written about him. 

Fragments of the story were out there, including Van Cise’s own book, “Fighting the Underworld,” but a lot of pieces were missing. I decided to try to track them down.  

SunLit: Tell us about creating this book. What influences and/or experiences informed the project before you sat down to write? 

Prendergast: I wanted it to be fun to read, completely factual but with an emphasis on character and narrative, like Erik Larson’s “Devil in the White City.” I wanted to capture a special time and place, a forgotten chapter of Denver history — and tell that story with the urgency of a heist novel.  


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And I was strongly influenced by David Maurer’s “The Big Con,” one of the best books about how con men operate and the arcane slang they use. 

SunLit: You describe a fascinating world of grifters and confidence men working in and around Denver. How did Colorado become such a destination for those crooks and earn a reputation as the Big Store?

Prendergast: The emerging tourism industry was one factor. Wealthy marks would come to Colorado on vacation; the con men would befriend them at places like the Broadmoor, the Brown Palace, or Manitou Springs and introduce them to a fake stock exchange in downtown Denver. 

But what made Denver such an ideal haven for big-con operations was its long history of graft and bribed cops. The fix was in — until Van Cise arrived.

SunLit: Portions of “Gangbuster” delve into Colorado’s history with the Ku Klux Klan. As racial tensions have escalated in recent years, and white nationalists have come under renewed scrutiny, do you see a particular relevance for Van Cise’s legacy today? Were there lessons learned – or not learned?

Prendergast: I tried to avoid glib comparisons between the Klan of the 1920s and, say, the Proud Boys. But the parallels are certainly there, particularly in the ways extremist movements tend to bamboozle their own followers. 

The Klan was great at marketing itself, spreading outrageous conspiracy theories, and exploiting people’s fears and bigotry for its own purposes and profit. But the leadership’s greed and corruption became major contributors to its rapid collapse. 



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I think we can still learn a lot from Van Cise’s example — the way he investigated the group as a criminal enterprise, exposed its lies, and fought the Klan takeover of the Republican party in Colorado has some relevance for how to deal with threats to democracy today. 

SunLit: There is such a rich cast of characters in the book, and so many of them. Tell us a little about the research behind the narrative.

Prendergast: I read plenty of old newspaper reports and standard histories of Colorado, but the real pleasure was delving into the archival materials — court records, surveillance notes, undercover reports of Klan meetings, oral histories, diaries, speeches, letters, and other documents. 

There’s a live-wire jolt you get from connecting with these sources, some of them a hundred years old and quite revealing. The past is a lot closer than we realize. 

SunLit: Once you began researching and writing, did Van Cise’s story take you in any unexpected directions? 

Prendergast: I don’t know if it was unexpected, exactly, but I struggled a bit with how to address Van Cise’s hardliner views on immigration. I didn’t want to minimize this side of him, as it helps to explain why the Klan was trying to recruit him when they weren’t trying to destroy him; they equated conservatism with white supremacy, which Van Cise clearly did not. 

In the end, it was better to have a complicated human being at the center of the story than a boring superhero. 

SunLit: Of course, the Van Cise name now graces the Denver detention center, but have you found that current law enforcement officials are familiar with his story? Has his legacy lived on as something more than a historical figure?

Prendergast: I don’t think his story is nearly as well-known as it should be, locally or nationally. Although he had a distinguished legal career after leaving the DA’s office, he was also shunned because of the stand he took against the Klan and corruption. 

His legacy depends on people being more willing now to acknowledge and examine the more shameful moments of our history and recognize the people who stood up for what was right, even though it was not a popular thing to do. That’s one reason for writing this book. 

SunLit: Walk us through your writing process. Where and how do you write? 

Prendergast: I write standing up and sitting down, thanks to an adjustable desk. Mornings are better for getting words on the page, afternoons are better for revision. But it seems like I am always revising. 

SunLit: What is your favorite scene in the book?

Prendergast: I’m fond of several sort-of-cinematic episodes dealing with investigating and busting the con men, including the antics of an unlikely undercover agent named Norfleet, a Texas rancher who’s swindled by the gang and concocts a magnificent revenge. 

But my favorite scene is probably the showdown between Van Cise and a horde of Kluxers bent on disrupting his speech at the Denver City Auditorium, a confrontation that goes on for five hours — and 10 pages — and demonstrates how useless logic and hard evidence can be when you’re being stampeded by a mob of true believers.  

SunLit: Tell us about your next project.

Prendergast: Whatever it is, I hope it will be as much fun as this one. 

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