'The Sing Sing Files' chronicles work to free the innocent

For decades, producer Dan Slepian has spearheaded documentaries, podcasts and investigative reports for Dateline NBC. In 2002, a chance conversation propelled him to start probing wrongful convictions, work that led to a Pulitzer Prize-winning podcast 20 years later. Slepian joined Amna Nawaz to discuss his new book, "The Sing Sing Files," and why the issue continues to fuel his work.