NEW YORK (CBSNewYork/AP) -- New York City police Commissioner Bill Bratton ended his unparalleled law enforcement career with a ceremonial send-off Friday.
Bratton, 68, participated in a traditional "walkout'' at NYPD headquarters, where commanders lined up in formation to bid him farewell as he leaves three years into his second stint as the city's police commissioner.
Law enforcement officials clapped enthusiastically as Bratton and his wife, Rikki Klieman, walked through 1 Police Plaza in downtown Manhattan on Friday afternoon.
The NYPD released Bratton's retirement letter to Mayor Bill de Blasio, in which Bratton told the mayor that "serving as police commissioner during your administration has been one of the great honors of my life."
"In leading six different police departments across the country in the past 35 years, I have never been better resourced or more fully supported by any mayor," he said. "From equipment, to training, to technology, to policy, to the first substantive headcount expansion in more than a decade, you have stood by the NYPD and made much of what we have accomplished possible."
He also thanked the "people of New York and the cops of the NYPD."
"It is impossible to quantify the many acts of bravery, kindness, and concern that our officers perform each day, but I am deeply grateful for their acts and for the privilege of working beside them for the past 33 months," he said.
Bratton also tweeted a picture Thursday night of himself posing with incoming Commissioner James O'Neill, as the two went on a final patrol together of the city transit system.
O'Neill told CBS2's Marcia Kramer that the trip helped him make the transition from uniform-wearing chief of department to suit-wearing commissioner.
"We did our last train patrol last night, the commissioner and I," O'Neill said. "So I think I'm ready."
O'Neill has now officially taken over, as 1010 WINS' Al Jones reported.
"For the record, I am now the commissioner, yes I am, and as soon as I go inside, I have to take this uniform off," he said.
O'Neill promised a seamless transition.
"My primary responsibility was to keep the people of this city safe, and I'm going to continue to do that. The people of this great city have my vow that I will keep them safe," he said.
Meanwhile, Bratton spoke exclusively to CBS2 outside of his home after Friday's ceremony about what his next steps will be.
"We have a dinner tonight with a couple hundred good friends. A lot of them have come in from out of town," he said. "Quiet weekend. Monday I start at my new job and also head down to police headquarters and see Jimmy O'Neill formally sworn in."
Bratton's new job will be as senior managing director and executive chairman of Teneo, an advisory firm focusing on cyber risks and data security.
The ceremony came just a week after Bratton fiercely defended the legitimacy of his signature "broken windows'' strategy -- an idea first proposed by social scientists James Wilson and George Kelling that violent crime can be deterred by cracking down on lesser types of lawlessness, such as graffiti or turnstile jumping.
Bratton earned wide acclaim for his assaults on so-called "quality of life'' crimes and for mining crime data to deploy his forces more effectively.
New York City's homicide rate had already begun to drop in the two years before he became commissioner the first time in 1994, but during his 27-month tenure it plummeted. Between 1993 and 1995, killings fell by 40 percent, erasing two decades of climbing murder rates.
Homicides fell another 35 percent in the two years after Bratton left the department, forced out by then Mayor Rudy Giuliani.
In more recent years, though, some criminologists have concluded that the impact of broken windows on violent crime is minimal.
In March, the independent inspector general for the NYPD issued a report concluding that focusing on offenses such as urinating in public and riding bikes on sidewalks had no influence on felony crime rates.
He also accused the 36,000-officer department of unfairly singling out communities of color for quality-of-life enforcement at a time when de Blasio has emphasized protecting civil rights.
Bratton pushed back last week with characteristic aplomb, saying the report was the work of "amateurs'' and had "no value at all.''
There is no consensus today about what caused New York City's turnaround in the 1990s or what caused similar, dramatic improvements in violent crime rates in many other U.S. cities at the same time.
"The idea that the NYPD has a huge impact on crime was always a very dubious claim,'' said Eugene O'Donnell, professor of police studies at John Jay College of Criminal Justice.
After leaving New York the first time, Bratton worked in the private sector, then took over a scandal-scarred Los Angeles Police Department in 2002.
There, he presided over both a decline in violent crime and an easing of some tensions between the department and black and Hispanic communities. Bratton left Los Angeles in 2009 with high approval ratings.
After returning to lead the NYPD again in 2014, Bratton saw perhaps the biggest crisis of his tenure: the death of an unarmed black man, Eric Garner, at the hands of a white police officer trying to arrest him for the minor crime of selling loose cigarettes.
The death sparked angry protests. It also fueled a backlash in some quarters against broken windows enforcement.
That outcry, though, hasn't caused city leaders to back away from the tactics, or the man often credited with leading New York out of the darkness.
"The same strategy that helped make us the safest big city in America,'' de Blasio said recently, "is still making us the safest big city in America.''
O'Neill, meanwhile, takes over the NYPD with crime at an all-time low and with increased concerns about quality-of-life issues such as the homeless, communities overrun with people who smoke synthetic marijuana and heightened racial tension.
The mayor is counting on O'Neill's community policing policies to deal with that.
"He has made community policing the hallmark and stable of his entire police career," said Phil Walzak, a senior adviser to de Blasio. "He's going to bring that philosophy to the department."
O'Neill is the first commissioner in several decades to rise through the ranks. A son of East Flatbush, Brooklyn, O'Neill is not expected to be a so-called "celebrity commissioner," unlike Bratton and his predecessor, Ray Kelly, who enjoyed hobnobbing with the glitterati and wearing designer suits and ties.
"He's known as a cop's cop," Walzak said. "He's very well-respected by the men and women in the ranks of the NYPD."
O'Neill is also a die-hard Rangers fan, ride a Harley Davidson and is called "J-Po" by the rank and file, for "Jimmy Police."
Police experts expect a lot of O'Neill.
"He knows the NYPD inside and out, but he's not afraid to say we need to change the way we do business," said Richard Aborn of the Citizens Crime Commission.
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