MONROE, N.Y.  — As bagpipers marched silently to the beat of a somber drum, a New York City police officer killed by friendly fire during a struggle with an armed man was honored at his funeral Friday as a hero and a dedicated, compassionate professional who put his heart into his work.

Officer Brian Mulkeen, who was hit Sunday by two police bullets while wrestling with the man in the Bronx, was the second New York City officer killed by friendly fire this year.

“We are here to honor a hero” and to “celebrate the life of an absolutely remarkable man,” said Police Commissioner James P. O’Neill, who choked back emotion as he addressed mourners.

Mayor Bill de Blasio said that Mulkeen “understood that his work required his whole heart and all the compassion that was in him.” He kept in touch with a teen he’d arrested, inviting him to play basketball.

“He undoubtedly changed the direction of that young man’s life,” said de Blasio, adding that the family was “devastated” by Mulkeen’s death, “as if they’d lost a family member too.”

Officers in dress uniforms stood at attention outside the church in Monroe, north of New York City. They crisply saluted as Mulkeen’s flag-draped casket was carried inside.

Mulkeen, who joined the department in January 2013, was working with a plainclothes anti-crime unit when he and his partners encountered the armed man.

The man fled on foot and officers chased him. Mulkeen and the man started to wrestle.

Police have described a chaotic confrontation in which 15 shots were fired in 10 seconds by six officers. Deputy Chief Kevin Maloney said five of those shots came from Mulkeen after the armed man reached toward his waistband.

The armed man was also killed in the gunfire.

Only one person was responsible for Mulkeen’s death, O’Neill said at the funeral: the man who “carried a “loaded and illegal gun and decided to run from police.”

Mulkeen was a graduate of Fordham University’s business school, and he worked as a financial adviser for Merrill Lynch from 2007 to 2009. He lived in suburban Yorktown Heights with his girlfriend, who is also a police officer.