The cause was melanoma and heart disease, said his wife, Catherine M. Coles.
Dr. Kelling, a onetime social worker, probation officer and supervisor of a residential program for troubled youths, began investigating police tactics and crime prevention in the 1970s.
In 1982, while he was a fellow at the Kennedy School of Government at Harvard University, he and Wilson published an article in the Atlantic magazine under the title “Broken Windows.” In the article, they contended that urban crime does not develop in a vacuum: It is the result of social neglect and decay, in which small problems can lead to a breakdown of civic life.
“Social psychologists and police officers tend to agree that if a window in a building is broken and is left unrepaired, all the rest of the windows will soon be broken,” Wilson and Dr. Kelling wrote.
The “broken windows” theory has become a cornerstone of “community policing,” a broad approach toward crime prevention practiced by police departments throughout the country.
“Page for page, it has had a greater impact than any other article in serious policing,” Jeremy Travis, director of the Justice Department’s National Institute of Justice, told the Los Angeles Times in 1996.
Wilson, who died in 2012, was credited with coining the article’s evocative title, but much of the scholarship behind “Broken Windows” was done by Dr. Kelling. Working alongside police officers in Newark and Kansas City, Mo., he visited deteriorating, crime-ridden neighborhoods to determine what went wrong and what could be done to preserve a community’s sense of social order.
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“I learn from war stories, I learn from experience, I learn from what’s happening on the streets,” Dr. Kelling told the Milwaukee Journal Sentinel in 2007.
He was particularly interested in how police tactics had changed from the old-fashioned, neighborhood cop walking a beat to the “rapid response” method, in which police officers ride in cars, then drive quickly to places where crimes have been reported.
“My own experience told me when a police car went by, they were always on their way to do something else,” Dr. Kelling said. “And when foot patrol officers walked by, they were there for me.”
He and Wilson suggested in “Broken Windows” that police officers patrolling a neighborhood on foot became a part of a community’s fabric, instilling a sense of familiarity, safety and pride.
“The citizen who fears the ill-smelling drunk,” Dr. Kelling and Wilson wrote, “the rowdy teenager or the importuning beggar is not merely expressing his distaste for unseemly behavior; he is also giving voice to a bit of folk wisdom that happens to be a correct generalization — namely, that serious street crime flourishes in areas in which disorderly behavior goes unchecked. The unchecked panhandler is, in effect, the first broken window.”
In the 1970s, while conducting research for the Washington-based Police Foundation, Dr. Kelling became friends with William J. Bratton, a Boston police officer. In the 1980s and 1990s, Bratton led the New York Transit Police, and the Boston, New York City and Los Angeles police departments. Everywhere he went, he put the “broken windows” ideas into practice.
Under Bratton, police officers enforced laws against public drunkenness, evasion of public transportation fares and aggressive panhandling, including the “squeegee men” who confronted drivers waiting at stoplights. Police learned that people who committed small offenses were also likely to commit more serious crimes.
In New York, there were 2,262 murders in 1990 and more than 100,000 robberies. By 2017, the number of murders had fallen to 292 and the number of robberies to about 14,000. Police departments in cities including Washington, Houston, San Diego, Milwaukee and Seattle adopted some form of community policing, often with noticeable drops in crime.
Over the years, scholars have questioned whether the “broken windows” theory actually reduces crime. Critics have said the tactics unfairly target African American and Latino men, particularly after Eric Garner died in a police chokehold in New York in 2014 while being arrested for selling cigarettes on the street.
Dr. Kelling said the “broken windows” theory should not be confused with the harsh police tactic of “zero tolerance,” in which minor infractions lead to arrest.
“We don’t want police to just be making arrests,” he told the Los Angeles Times in 2015. “We want them to find solutions and at times that solution is simply deciding not to do anything, or saying, ‘You know you’re not supposed to be doing this, move along.’ . . . Arrests are not necessarily a desirable outcome.”
George Lee Kelling was born Aug. 21, 1935, in Milwaukee. His father was a firefighter, his mother a factory worker.
After spending two years at a Lutheran seminary, Dr. Kelling graduated from St. Olaf College in Northfield, Minn. He later received a master of social work degree from the University of Wisconsin at Milwaukee and a doctorate in social work from the University of Wisconsin at Madison.
After holding jobs as a social worker, probation officer and group-home supervisor, he began his research at the Police Foundation and later at Northeastern University in Boston. He later taught at Rutgers University at Newark and was a longtime fellow of the Manhattan Institute think tank.
With his wife of 36 years, Coles, he wrote “Fixing Broken Windows: Restoring Order and Reducing Crime in Our Communities” (1998).
His first marriage, to Sally Jean Mosiman, ended in divorce. In addition to his wife, of Hanover, survivors include two children from his first marriage and four grandchildren.
Dr. Kelling continued to advocate the “broken windows” theory for years, and it was adapted from policing to business as a way to foster urban renewal.
The goal of civic life, he said, was not the “zealotry and no discretion” of an unsupervised police force, but a peaceful environment where people could live in harmony.
“In an urbanized society, in a world of strangers,” he told the New York Times, “civility and orderliness is an end in itself.”
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