Pals of slain NYPD Officer Brian Mulkeen remembered the hero cop as a “fabulous person” who had a strong “calling to protect people.”

“He was a special person,” said Dan Tucker, 34, who met Mulkeen at Fordham University where they were both on the track-and-field team.

“We became friends immediately. We bonded over music. We used to play guitar all the time,” said Tucker, a sergeant for the Salem Police Department in Massachusetts.

Tucker recalled how Mulkeen always wanted to play “Wild Horses” by the Rolling Stones, adding, “It was one of his favorite songs.”

“He was a friend to everybody who needed it,” said Tucker. “One moment he’d be entertaining a group of people with a Chris Farely or [Arnold] Schwarzenegger impression, but if you needed him to talk to you, he was an incredible listener.”

After graduating from Fordham, Tucker moved to Boston, but kept in touch with Mulkeen every time he returned to New York City.

Tucker remembered how eight years ago Mulkeen – who got a “big-money” job at Merrill Lynch after school – called him up to say “he was quitting his job and that he was going to become a cop.”

“It was incredible hearing his voice,” said Tucker. “He said he felt like it was a calling, like he wasn’t making enough of an impact in what he was doing.

“He said to me, ‘I want to get out there and make a difference. I’m not just saying that, I really want to get out there and make a difference.’ ”

Tucker continued: “He’s the definition of a hero in my book … He gave up a big-money job to work in the most dangerous places because he felt a calling to protect people.”

Mulkeen, 33, was fatally shot by friendly fire early Sunday in the Bronx following a violent struggle with an ex-con.

And Tucker said the night of his death “95% of people were asleep in their beds and Brian was out there to make sure that they could be sleeping safely.”

Bronx resident Brian Horowitz, 31, also knew Mulkeen from Fordham’s track-and-field team.

“Brian was a real leader on the team, someone we could look to, to set the tone for the team,” Horowitz said. “He was full of energy and passion. It was contagious. He was a great competitor.”

Horowitz took over the team as head coach this past summer and reached out to Mulkeen to lend a hand and he gladly accepted.

Mulkeen, a 2-year field captain for Fordham and star athlete, rejoined his alma mater as a volunteer throwing coach alongside Horowitz.