The FBI confirmed Monday that Donald Trump’s right: America’s murder rate is spiking. New data show homicides rose 11 percent in 2015, with overall violent crime up 4 percent.

Trump rightly warned that this is a particular crisis for poor minorities, since the rise is mainly an urban one: “Homicides last year increased by 17 percent in America’s 50 largest cities,” he said. “That’s the largest increase in 25 years.”

Critics huffed — but the fact-checkers had to concede he’s right. The Washington Post confirmed Trump’s figure in July. The New York Times this month said murders soared 14 percent in the 100 biggest cities, with half the jump coming from just seven: Baltimore, Chicago, Cleveland, Houston, Milwaukee, Nashville and Washington.

New York City actually was part of the grim 2015 trend, with homicides up 6 percent. But the NYPD took aggressive steps to adjust, and 2016’s numbers are looking much better.

Chicago and too many other cities aren’t so fortunate.

The grim news also vindicates the Manhattan Institute’s Heather Mac Donald, who’s long warned of the “Ferguson Effect”: less-aggressive policing in the wake of anti-cop protests and rioting.

Cops in urban areas, she’s written, fear being called racists. They’re “backing off of discretionary, proactive policing,” worried that “any use of force against a black civilian . . . could put their career at risk.”

FBI chief James Comey points to the same problem. And ex-NYPD Commisioner Bill Bratton cited what he called “the YouTube Effect.”

The left is eager to deny the trend, noting that crime is still far below 1980s levels. Are we not supposed to complain until it’s gotten that bad again?

Then again, liberals can’t bear any criticism of the Black Lives Matter movement — no matter that its impact seems to mean the end of more black lives. Hillary Clinton even made the “Mothers of the Movement” a major presence at the Democratic convention.

Anything rather than recognize the truth: Good policing — proactive, aggressive policing — matters. And politicians who don’t support it have blood on their hands.