By: Dean Weiner

Former NYPD commissioner Ray Kelly is speaking out publicly for the first time about a Rikers Island inmate’s plot to behead him and bomb police headquarters some 16 years ago and it will air on the popular TV program “Undercover: Caught on Tape” on A&E network

But Kelly wasn’t scared, the longest-serving commissioner in NYPD history told The Post in an interview ahead of a new A&E docu-series detailing how authorities foiled the 2007 scheme.

“We had this guy identified, and he was in prison,” Kelly, 81, said to The New York Post, recalling David Brown Jr.’s plan to hire a hitman to kill and dismember him.

“I felt relatively secure,” Kelly, who led the department between 2002 and 2013, said cooly. “It really didn’t jolt me that much. You probably don’t want to hear that, but that’s pretty much what it was.”

The chilling plot was ultimately stopped thanks to the work of an undercover officer — with Kelly lauding him and other such investigators as unsung heroes write Georgett Roberts and Steve Janowski of The New York Post.

According to The New York Post, That was all authorities needed. Brown was arrested and charged with two counts of solicitation, ultimately receiving an additional six years behind bars.

NYPD Detective Chuck Byam cracked the case.

“Well, what I need to do is have the police commissioner killed – I want him murdered,” Brown told Byam on a clip of the first episode of “Undercover: Caught on Tape” set to air Thursday.

“I made a difference in ordinary, everyday New Yorkers’ – I made a difference in their lives,” Byam said.

“Although they’ll never know I was the one responsible for it, I still feel good about the difference I’ve made in New York City.”

People did notice, though. Then-President Barack Obama sent the detective a congratulatory letter, and New York Sen. Chuck Schumer sent him a flag that had flown over the nation’s Capital in his honor, Byam told The Post.

“I felt very honored,” he said in an interview last week. “The fact that I was still alive when I got the flag — that was definitely a honor for me, a touching moment.”

Kelly was reportedly never in any direct danger. Brown, who had been convicted of 30 crimes, was mentally ill and wheelchair bound.

Still, Kelly told The New York Post that he was “certainly glad [Byam] was there.”

“He did a great job,” Kelly said. “You know, you don’t think about those things in the normal course of business … but when you are confronted with something with all of those details, the specificity of the threat, then it gives you cause for concern.”

According to his Wikipedia page, Ray Kelly was born September 4, 1941 and is the longest-serving Commissioner in the history of the New York City Police Department (NYPD) and the first man to hold the post for two non-consecutive tenures. According to its website, Kelly — a lifelong New Yorker—had spent 45 years in the NYPD, serving in 25 different commands and as Police Commissioner from 1992 to 1994 and again from 2002 until 2013.

Kelly was the first man to rise from Police Cadet to Police Commissioner, holding all of the department’s ranks, except for Three-Star Bureau Chief, Chief of Department and Deputy Commissioner, having been promoted directly from Two-Star Chief to First Deputy Commissioner in 1990. After his handling of the World Trade Center bombing in 1993, he was mentioned for the first time as a possible candidate for FBI Director.