Lt. Jack Cambria has spent more than a decade talking people down from the ledge. Until his retirement in 2015, he was the commanding officer of the NYPD's hostage negotiation team for over 33 years. During his career he became an expert at saving fellow cops from gun-wielding maniacs or dissuading people to not jump off New York City's skyscrapers or bridges.

What's the secret to success as a hostage negotiator? Cambria says, "The very good negotiators, I think, are the ones with the life stories"—particularly, he would add, life stories of pain that have produced compassion for others. Cambria claims, "[Good negotiators must] experience the emotion of love at one point in their life, to know what it means to have been hurt in love at one point in their life, to know success and perhaps, most important, to know what it means to know failure."

He learned this lesson during his first day as a police officer. Cambria admitted that he had his "own baggage about the homeless, they were violent, they were dirty, they were mentally ill." Then one day, he had to confront a homeless fare beater and searched his satchel. Inside wasn't a weapon but a manuscript of a play titled "Crabs in a Basket," a metaphor for the man, of his struggle to crawl out of the hole he was in.

"In that two-minute space of time, he had transposed himself from a homeless guy—my baggage—to a playwright," he recalled. That compassion has led colleagues to refer to him as "Gentleman Jack," whose guiding principle is to just get the suspects talking.