Former and incoming New York Police Commissioner William Bratton w. Mayor-Elect Bill de Blasio (Seth Wenig/AP) Former and incoming New York Police Commissioner William Bratton, left, and Mayor-elect Bill de Blasio (Seth Wenig/Associated Press)

By naming William Bratton as his police commissioner, New York City Mayor-Elect Bill de Blasio is sending mixed signals. I mean that more positively than it might sound.

When Rudy Giuliani became mayor in 1994, Bratton was his first police commissioner (1994 to 1996). Giuliani campaigned as a law-and-order candidate and viewed the fear of crime by New Yorkers was as pernicious as crime itself. He earned great praise for the ensuing rapid decrease in crime because of the adoption of the broken windows theory of policing made famous by James Q. Wilson and George L. Kelling in a March 1982 article for the Atlantic Monthly. So, too, did Bratton, whose acclaim eventually got him fired.

That Bratton was a Giuliani police commissioner can’t sit too well with de Blasio’s most ardent supporters. De Blasio rode from back of the pack to top of the heap largely on a wave of anger against stop-and-frisk, a policing tactic implemented by Giuliani and expanded by his successor, Mayor Michael Bloomberg. How the new mayor who campaigned to end it and his new police commissioner go about doing this will be fascinating to watch.

But the Bratton appointment does something more psychic for New Yorkers. All that loose talk that crime would explode under de Blasio goes away. The city gets a top cop who presided over the initial drop in crime in the 1990s and whose work reforming the Los Angeles Police Department from 2002 to 2009 reformed his image back in New York. So much so that Rev. Al Sharpton tipped his hat to Bratton in a statement today.

When Bill Bratton served in New York City under Rudy Giuliani, we had a very distant and adversarial relationship, but when he served in Los Angeles, he and I and the Los Angeles Chapter of National Action Network worked closely on gang violence and police misconduct matters. Mr. Bratton knows of my concerns and the concerns of others about racial profiling in stop and frisk policing but at the same time is aware of our desire to continue the decrease of violence and crime in our community.

Another tidbit that will be of comfort to the Big Apple establishment is that since 1992 there have been just four police commissioners. Howard Safir (1996 – 2000) was a total dud. Bernard Kerik (2000 – 2001) proved more charismatic — and criminal. Still, all categories of crime continued to plummet on their watch. Perhaps because everyone just assumed all the shots were being called not by the commish at One Police Plaza but directly by Hizzoner at City Hall.

Here’s one more thing: Current Police Commissioner Ray Kelly, who was appointed by then-Mayor David Dinkins in 1992, was succeeded by Bratton when Giuliani assumed office in 1994. Come Jan. 1, 2014, exactly 20 years later history will repeat itself.

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Jonathan Capehart is a member of the Post editorial board and writes about politics and social issues for the PostPartisan blog.