After more than three decades serving the city, NYPD Chief of Detectives Robert Boyce is retiring.

From the day he first donned his gun and badge, and up until the day he walks out as New York's former top detective, Boyce says it has been a journey.

"I'm very proud of it," says Boyce. "Of what happened in this city in the last 35 years."

Chief Boyce has seen the city transform. He was on the frontlines of some of its worst days, he says, working with the hope of seeing better ones.

His passion for change, Boyce says, started early on in his career.