Standing on the dais at Madison Square Garden, Mayor Bill de Blasio faced 884 new officers marking their graduation from the police academy Monday.

The mayor praised the men and women, wearing their dress blues and white gloves, for choosing a heroic profession but one fraught with challenges.

“You will confront all the problems that plague our society, problems that you did not create,” de Blasio told the officers.

A heckler deep in the stands shouted at de Blasio. But the mayor continued speaking even as some applauded the outburst.

“You'll confront poverty, you'll confront mental illness, illegal guns and a still too divided society. All of these challenges,” said de Blasio. "You didn’t create these problems but you can help our city to overcome them. You can be part of the solution. And that is a blessing. That is a worthy calling." 

It’s not uncommon for mayors to receive a prickly reception at NYPD graduations — Mayors Bloomberg and Giuliani both faced boos. The anger at de Blasio came amid ongoing tension over the deaths of Officers Wenjin Lu and Rafael Ramos; the ongoing protests against the department; and unsettled union contracts.

When it was his turn to address the graduates, Police Commissioner Bill Bratton acknowledged that tension.

“We are in a very difficult time at this time in this country in this city, in this department," he said. "But we will work forward through it. We always do.”

Both the mayor and Bratton talked about the administration’s commitment to ongoing training of all NYPD officers and 21st century technology including tablets and smartphones.

Outside the arena, Norma Bartley was among the many proud parents. Her 29-year-old son Christopher is a newly minted cop. He's also a former Marine who served two tours in Iraq. They are both black. She sympathized with the protesters — and the cop families that are offended by them.

“It's dangerous on both sides, so I can understand the boos and I can understand the reaction too from the crowd,” said Bartley.

But Bartley said she thinks the city can overcome the current tension, and for her son’s sake, offered her own coping mechanism:

“A whole lot of praying," she said. "A whole lot.”