Washington Post Fact Check Debunks Claim That Eliminating Stop-And-Frisk Increased Crime 

Wash. Post: No Evidence Stop-And-Frisk Reduced Crime.  The Washington Post's Fact Checker blog found no evidence to support a claim by Gov. Mike Huckabee that “shootings are up 20 percent in New York City” because of New York Mayor Bill de Blasio's reversal of “some of the policies of previous mayors,” notably stop-and-frisk - a New York City Police Department  practice ruled unconstitutional in 2013. Kessler pointed to a study by the New York Civil Liberties Union showing that New York City's “decline in shootings and murders did not correspond with increase in stops.” Kessler also pointed out that crime continued to fall in 2013 and 2014 as the policy was slowed down, and in fact 2013 was “a historically low year” for shootings:

By the time de Blasio took office, the program already was on its way out. After the number of stops peaked at nearly 700,000 in 2011, it began declining. In 2013, there were fewer than 200,000 stops. In 2014, there were just under 46,000, according to NYPD data.

Supporters of the program warned that violent crime would go up without stop-and-frisk. But violent crime was down across the city in 2014, the New York Times found.

[...]

The number of violent crimes in New York City has decreased from 2000 to 2014. The number of shooting victims are down nearly 20 percent since five years ago, and 77 percent since 22 years ago, according to NYPD.

Whether stop-and-frisk effectively reduced murder and violent crime is debatable. A 2014 New York Civil Liberties Union report showed that the decline in shootings and murders did not correspond with increase in stops.  [The Washington Post, 7/1/15]  

Wash. Post: 98.5 Percent Of Frisks Found No Weapon. The Post also noted that “98.5 percent of the 2.3 million frisks” conducted between 2004 and 2012 did not result in a weapon being found:

Whether stop-and-frisk effectively reduced murder and violent crime is debatable. A 2014 New York Civil Liberties Union report showed that the decline in shootings and murders did not correspond with increase in stops. The federal judge who ruled the practice unconstitutional also found that in 98.5 percent of the 2.3 million frisks between 2004 and 2012, no weapon was found. [The Washington Post, 7/1/15]    

Fox News Has A History Of Erroneously Blaming Stop-And-Frisk Rollback For Increased Crime

Bill O'Reilly: Bill De Blasio Is Allowing Criminals To “Roam Around With ... Guns.” On the May 12 edition of Fox News' The O'Reilly Factor, Bill O'Reilly blamed New York City's crime increase on Mayor Bill de Blasio's decision to abandon stop-and-frisk policies. O'Reilly characterized the mayor's actions as public endangerment, saying de Blasio was allowing criminals to “roam around with the guns.” Guest Lis Wiehl claimed that “the rollback of stop-and-frisk means there are more criminals out there carrying guns.” [Fox News, The O'Reilly Factor, 5/12/15]

Fox Host Guilfoyle: New York's Increase In Rapes Can Be Tied  “In Part To Stopping Stop-And-Frisk.” On the June 9 edition of Fox News' The Five, co-host Kimberly Guilfoyle linked an increase in rapes in New York during the first months of 2015 to “stopping stop-and-frisk”:

GUILFOYLE: The problem is, there are real issues right now on the streets of New York that I think can also tie in, in part, to stopping stop and frisk. [Fox News, The Five, 6/9/15] 

Fox's Andrea Tantaros: The Drop In Stop-And-Frisk Tactics “Has Reportedly Emboldened Criminals.” On the June 5 edition of Fox News' Outnumbered, co-host Andrea Tantaros cited the decrease of New York's stop-and-frisk policy as the reason for an uptick in violent crime, saying it had “reportedly emboldened criminals.” Tantaros praised the policy, saying it helped decrease black-on-black crime:

TANTAROS: Well, a dramatic drop in stop-and-frisk encounters in New York City has reportedly emboldened criminals and had a chilling effect on the way police are doing their jobs. 

[...]

When you look at the stats on stop-and-frisk, stop-and-frisk was put into place, New York City, it helped clean up the city. The proactive policing policies of Rudy Giuliani turned the city around from years of progressive failures. And really it benefits the black-on-black crime. It really helped get rid of that the most. [Fox News,Outnumbered, 6/5/15] 

Geraldo Rivera: Stop-And-Frisk “Has Been The Most Effective Tool To Keeping Guns Off The Street.” On the June 5 edition of Fox News' Fox & Friends, Fox contributor Geraldo Rivera endorsed stop-and-frisk, saying the policy “has been the most effective tool to keeping guns off the street.”  Rivera also described de Blasio's rollback of stop-and-frisk as “irresponsible”:

RIVERA: I lived through the bad old days where there were over 2,200 murders every year. 2,200 murders every year, now we're down to 300.  One of the great tools the cops have used to reduce this carnage, which, after all, is mostly involving victims who are black or brown, minority kids are the ones whose lives have been saved. From 2,200 to 300 a year and the tactic of stop, question and frisk, which is constitutional, based on reasonable suspicion, has been the most effective tool to keeping guns off the streets.

[...]

Remember that of the, the difference between 2,200 and 300, so now you have 1800, 1900 lives every year, saved, times the twenty, that's like 30,000 minority lives in New York City alone have been saved by stop-and-frisk. [Fox News, Fox & Friends, 6/3/15]