NEW YORK (Reuters) - About half of New York City's police arrests using the controversial stop-and-frisk tactic lead to convictions and about a quarter lead to prison sentences, according to a report released on Thursday by the state's top prosecutor.
The New York Police Department's aggressive use of the tactic has been at the center of a roiling debate that has sparked lawsuits, polarized the city and helped drive a long-shot mayoral candidate to a historic landslide victory.
The report by New York State Attorney General Eric Schneiderman analyzed 150,000 arrests that resulted from 2.4 millions stops by the NYPD between 2009 and 2012.
The analysis was billed by Schneiderman's office as the first of its kind.
"Until now, no known study has sought to assess what happens following (stop-and-frisk) arrests," the report said.
It found that 51 percent of arrests from NYPD stops led to convictions or guilty pleas.
The other half were never prosecuted, dismissed or resulted in adjournments in contemplation of dismissal - a legal term for cases in which a judge allows a case to be dismissed after a probationary period of usually six months to a year.
The report also said the stop-and-frisk arrests resulted in a 24 percent incarceration rate.
The chief spokesman for the police, John McCarthy, called the analysis "flawed" and said it underestimated the value of the tactic.
He said it fails to account for situations in which police action such as stop and frisk deter or prevent a crime, which does not result in arrests.
The report results appear to show that the outcomes of stop and frisk arrests are no more or less effective in nabbing criminals than are other NYPD arrests.
The conviction and incarceration rates in the Schneiderman report are nearly identical to the rates for overall city arrests last year, according to statistics from the New York State Division of Criminal Justice Services.
Melissa Grace, a spokeswoman for Schneiderman, said the report did not compare the conviction and incarceration rates resulting from police stops with overall citywide rates.
She declined to elaborate on the similarity of the figures.
The NYPD's use of stop and frisk has been at the center of a contentious debate since May 2012 when the New York Civil Liberties Union released a report showing use of the tactic skyrocketed under Mayor Michael Bloomberg.
The total number of police stops rose from 160,851 in 2003 - a year after Bloomberg took office - to 685,724 in 2011.
Bloomberg and police Commissioner Ray Kelly have staunchly defended the tactic as the centerpiece of a crime-fighting strategy that has driven overall crime down more than 30 percent during Bloomberg's three terms in office.
In August, a federal judge ruled that the police use of stop and frisk led to "indirect racial profiling" of mostly young, minority residents - who comprised 87 percent of all police stops last year.
The judge, U.S. District Court judge Shira Scheindlin, appointed a federal monitor to oversee a broad spectrum of reforms aimed at curbing the practice.
Last week, Scheindlin's ruling was put on hold and she was removed from the case by a three-judge appellate panel which said she "ran afoul" of the judicial code of conduct by granting media interviews and appearing to steer the lawsuit to her courtroom.
The case has been re-assigned to another judge but is expected to be withdrawn after Mayor-elect Bill de Blasio takes office on January 1.
De Blasio, a Democrat, made reforming police use of the stop and frisk policy a key component in his mayoral campaign. He won a landslide victory over Republican Joseph Lhota, who supported the stop-and-frisk tactic.
Reporting by Chris Francescani; Editing by Ellen Wulfhorst and Ken Wills