The lanky black detective strode to the front of the school auditorium, grabbed the microphone and turned to face the crowd. He had a feel for the room, for the mistrust and doubt in many hearts, and a strategy to win them over.

But would his pitch work?

In his 14 years as a New York City police officer, Detective Yuseff Hamm has stalked drug dealers, chased gunmen and talked two men out of jumping off buildings.

But as he stood last Tuesday before a predominantly black audience at a community meeting in Rosedale, Queens, he faced a challenge that some might argue was nearly as daunting: Trying to persuade African-Americans to join the city’s Police Department in the Eric Garner era.

About a quarter of the city’s population is black and yet, Detective Hamm told the crowd, “in the Police Department, it’s only 16 percent.”