Former ABC News correspondent Peter Lance shares his investigative findings regarding mobster Greg Scarpa Sr. in Deal with the Devil: The FBI’s Secret 30-Year Relationship with a Mob Killer.

What turned you on to the story of Greg Scarpa Sr.?

My investigation of the FBI’s counter-terrorism failures on the road to 9/11 and beyond, which I wrote about in my first book, 1000 Years for Revenge. I proved that it was Ramzi Yousef who conceived the 9/11 plot in Manila in the fall of 1994 after he’d fled New York City [in the wake of the 1993 bombing of the World Trade Center, for which Yousef was responsible]. Incredibly, Yousef spent 11 months in a cell next to Gregory Scarpa Jr., the son of a bloodthirsty capo in the Colombo crime family who had worked as an informant for the Bureau for more than 30 years. That led to my looking into Scarpa Sr.

Sometimes deals get cut with lower-level thugs to catch the big bosses, as when Sammy Gravano incriminated John Gotti. Are these deals with lesser devils necessary evils?

There’s a huge difference between making a plea bargain with a “Sammy the Bull” so he’ll flip on a Gotti, and actually employing a killer like Scarpa (who “stopped counting” after 50 murders) and using him as an effective “agent provocateur” to wreak havoc inside a mob family. The title of my book derives from a line in the dismissal of murder charges against Scarpa’s FBI handler, who was indicted on four counts of murder-conspiracy by the Brooklyn D.A. in a case that fell apart in 2007. Judge Reichbach wrote, “that a thug like Scarpa would be employed by the federal government… is a shocking demonstration of the government’s unacceptable willingness to employ criminality to fight crime.”

What was the hardest part of writing this book?

The scope of the story, which got bigger and bigger as I kicked over rocks. As I began to interview sources and finally gain access to secret FBI memos on the Bureau’s relationship with Scarpa, the book turned into an epic work. But what emerged for me from all of this research was an absolutely riveting story of manipulation by Scarpa, a Machiavellian chess master who played everybody around him, from senior FBI officials to the very members of his family, whom he betrayed.

Why have your discoveries not been picked up by the media?

The mainstream media is just as resistant to admitting that they may have been wrong in reporting a story and to correcting the record as institutions like the FBI are in revisiting their failures, copping to them, and correcting the system.