This biographer exchanged emails with Bernie Madoff from prison for a decade. Here’s what he learned

You probably haven't heard Bernie Madoff's name in awhile, but that doesn't mean the infamous fraudster's story is over, or the pain he inflicted.

Irving Picard, an 83-old court-appointed trustee, still spends his days trying to claw back money from the those who benefitted from Madoff's Ponzi scheme, and to reduce the staggering losses of others.

More than 100 legal battles over the greatest known fraud in history still rage on.

Richard Behar, who has just published a new biography, "Madoff: The Final Word," is also still trying to understand how Madoff's mind worked. What allows a person to rip off Elie Wiesel, who survived the Holocaust and went on to become a main chronicler of it? Or to sit with his wife, Ruth, in a theater and enjoy a movie while knowing that he's erased the life savings of thousands of people all over the world?

Those questions haunted Behar — who tells CNBC he has long been fascinated by con-artists. So long after most other reporters had turned their attention elsewhere, he reached out to Madoff while the financial criminal served out his 150-year prison sentence in North Carolina.

Behar started by sending his condolences to Madoff, whose son, Mark, had just died by suicide in Dec. 2010, the second anniversary of his father's arrest.

Shortly after, an email subject line popped up in Behar's inbox: "Inmate: MADOFF, BERNARD L." That message was the start to a decade-long relationship between the two men, including roughly 50 phone conversations, hundreds of emails and three in-person visits. When Madoff died in April 2021, Behar was still writing the biography. Madoff often complained to Behar that he was taking too long on the book.

"He once joked that he'd be dead when it came out, which of course