Last month, Mayor Bloomberg got all braggy about the city's 2012 murder rate dropping to the lowest level ever recorded, and lauded the NYPD—but it turns out Police Commissioner Ray Kelly and co. might not have had much to do with it. NPR recently asked a couple experts what the new numbers mean, and found aggressive police tactics like much-debated stop-and-frisk aren't necessarily the answer to lower crime rates.

The city saw 414 recorded homicides in 2012, down considerably from 2010's 536 and 2011's 515. But while Kelly and Bloomberg attributed the downtick to NYPD programs like Operation Impact, other factors besides that specific policy are probably responsible. "If you're gonna make the assumption that changes in crime rates always are responding to policies," Franklin Zimring, a law professor at UC Berkeley, told NPR, "then why shouldn't we be blaming the police for the slight increases [in New York's murder rate] in 2010 and 2011?"

Though Kelly made the point that if the NYPD ceased stop-and-frisk tactics—which many argue are unconstitutional—we'd all face a future filled with gun-wielding murder-robbers at every street corner, there are other ways to lower the crime rate. "If you look at the 50-year perspective, there are cities across the spectrum [where] crime rates have gone back to what their 1960 levels were, without having to resort to these tactics," Jeffrey Fagan, a law professor at Columbia University, told NPR. And as a matter of fact, stop-and-frisk stops dropped considerably last year.

So are New Yorkers really any safer now than they were in 2011, or is the murder rate drop just a one-time coincidence? Murder and crime stats have been dropping significantly since the 1990s (though overall crime rates did go up a little last year) so it's probably safe to say we don't live in the Bad Old Days anymore. On the other hand, it's still a little risky to daydream on the subway with your precious iPad on your lap.