Scott Olson / Getty Images Chicago Mayor Rahm Emanuel, pictured at a flag-raising ceremony at the Chicago Police Academy in October, said this month that "we will not rest" until Chicago's growing homicide rate is reversed.

New York Mayor Michael Bloomberg was crowing.

"The number of murders this year will be lower than any time in recorded city history," Bloomberg said Friday in a statement announcing that homicides in the city this year had fallen to 414 — the fewest since it started keeping such statistics in 1963.

About the same time Friday, Chicago police were trying to get the message out that their city hadn't actually recorded its 500th homicide this year, as was being reported. A few hours later, they had to backtrack and acknowledge that, yes, in fact, "the city has seen its 500th homicide for 2012."

That's right: There were more homicides this year in Chicago than in New York, a city with three times the population. That means Chicagoans were proportionally 3.7 times more likely to be homicide victims than New Yorkers were in 2012:

Overall, crime is down in Chicago in just about every category — except the most devastating one.

"We've obviously seen, as a city, our shootings and our homicides going in a different direction," Mayor Rahm Emanuel said this month at a graduation ceremony for police recruits, vowing, "We will not rest" until that trend is reversed.

Grim milestone: Chicago records 500th homicide of 2012

Meanwhile, in New York, "we're preventing crimes before someone is killed," Police Commissioner Ray Kelly said Friday.

New York didn't just reduce homicides — it reduced them by 19.6 percent. And Chicago didn't just have more homicides — it had 15.6 percent more.

Both figures are extraordinary. Last year, homicides fell by about 4 percent in New York, exactly in line with other U.S. cities with populations greater than 1 million, according to FBI figures. They fell in Chicago by just less than three-quarters of 1 percent.

While there's always the chance that the changes are just statistical flukes, two concrete factors appear to be at least partly responsible: money and priorities.

New York's police budget held steady in fiscal 2012, at about $4.6 billion.

Emanuel, facing a $300 million budget deficit, by contrast cut $67 million from the $1.3 billion police budget — a 5 percent reduction that was down from his original proposal to cut police funding by 15 percent.

While Emanuel and Chicago Police Superintendent Garry McCarthy said the cuts would help the police department become more efficient, Jens Ludwig, a criminal justice expert at the University of Chicago, said it was difficult "to think that you could have budget cuts like these and have no impact on crime and other aspects of public life."

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"I have been really surprised at how little attention the local and state budget situation has received in discussions about the Chicago violence problem," Ludwig told NBC News on Friday.

The other factor is commitment, Ludwig said.

"New York City seems to be exceptionally focused on getting illegal guns off the street," he said.

Ludwig drew an analogy to prosecution of drunken driving.

At one time, the official attitude was that "if the driver is lucky enough not to hurt anyone, it's no big deal," he said. "But (eventually) we started to realize drunk driving imposes probabilistic harm, and so we started to punish the risky behavior rather than focus on the luck of the draw about whether anyone happened to get hurt.

"New York City has taken that idea seriously for illegal gun carrying, recognizing that illegal guns on the street greatly increase the risk that an argument turns into a murder," he said.

Kelly, the New York police commissioner, stressed that point Friday, saying his officers had taken 8,000 weapons "out of the hands of people we stop, 800 of them illegal handguns."

"We're preventing crimes before someone is killed and before someone else has to go to prison for murder or other serious crimes," he said.

New York City homicides, shootings at modern record lows

Bloomberg made a similar point, singling out what he called the city's renewed commitment to Operation Impact, a 2003 state initiative that pairs new police recruits with veteran officers in specific high-crime areas. The city's participation "reflects our commitment to doing everything possible to stop gun violence," he said.

Left unmentioned was the city's controversial stop-and-frisk policy, which allows officers to search someone as he or she exits a private building if they have a "reasonable suspicion" that the person is likely to commit a crime.

"I think there is some empirical basis to think that all those hundreds and thousands of stops and searches for illegal guns helps keep guns off the street and contributes to a lower homicide rate," Ludwig said.

But the policy is under legal challenge from civil liberties groups, which contend that police use it as a pretext to stop and search people without cause — the great majority of them members of minority groups.

According to an analysis of raw arrest statistics by the nonprofit Center for Constitutional Rights, which opposes the policy, 84 percent of the 686,000 people stopped and searched in 2011 were African-American or Latino. Only 6 percent of the stops resulted in an arrest. And in only 2 percent of stops were illegal weapons or other contraband actually found.

Read the full report (.pdf)

Statistics like that make it worth asking "whether stop and frisk is worth the cost," Ludwig said. "All the stops come disproportionately to young, minority males."

A trial date is set for March. In the meantime, Bloomberg said Friday, New York remains "the safest big city in America."

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