"You have a radical left-wing mayor that is supporting the Black Lives Matter and supporting Antifa, told his police department to take a light touch in dealing with the protests that turned into riots that devastated the city," Kerik told guest host Raymond Arroyo.
"He let hundreds, if not a couple of thousand people off Rikers Island, has sent them home. Some of them very, major violent criminals."
"He has he's cut back 600 positions on the plainclothes anticrime unit, which is primarily responsible for taking guns off the streets and going after violent criminals in progress," Kerik said. "Every move he has made has been done in an attempt to diminish the police department."
New York City saw more than double the daytime shootings – those that occurred between 7 a.m. and 7 p.m. – from May 1 through July 31 than it did during the same period last year, as the Big Apple continues to grapple with the startling uptick in gun violence, Fox News has learned.
Kerik also disagreed with de Blasio blaming the coronavirus for people leaving the city.
"[De Blasio] is saying it's COVID. He's saying that people are leaving New York City in droves and moving to other states as a result of COVID. COVID is a virus, it is temporary. Nobody is going to leave their home, move out of New York City permanently because of a virus. Nobody is going to do that," Kerik said.
"But people are moving out of New York City because they're scared to death. Shootings are up in. Robberies are up. Murder is up."
The former top cop also blamed New York Gov. Andrew Cuomo for New York City's troubles.
"And I have to put some of the blame, Raymond, on the governor. He sees what's happening. He understands it. He gets it," Kerik said.
"Governor Cuomo was around in the 80s and early 90s with Giuliani and I and others came into office and had to change New York City and reduced the violent crime and murder. He knows how to get it done, how it got done. And he's doing nothing about de Blasio's failure and leadership as it stands today."