Before a grand jury decides whether an NYPD officer who choked an unarmed black man to death deserves to be punished, Mayor de Blasio reminds us that overall crime is down 4.4%. "The numbers…are just plain extraordinary," the mayor told reporters yesterday.

Here are those numbers: murder is down by 6.8% since last year, and 83% since 1993; rape has decreased 2.9%, and 58% over the last 21 years; robberies have declined 14.4% and 80%, the lowest amount ever recorded; crime in the subway is down 13.8%.

Shootings have increased slightly. So has auto theft. Violent crime in some NYCHA units has increased; in the Bushwick Houses, it's up 40%. But we're told that's the only bad news.

Since the NYPD began following the letter of the 1977 law that decriminalized marijuana, those low-level arrests for possession have declined by 61.2% in two weeks.

The drop in overall crime has also been accompanied by a decrease in stop and frisks by 79%.

"Although many were predicting stop, question, and frisk went down, crime would go up—doesn’t work that way," Commissioner Bratton told reporters, referring to the dire threats being made by the former administration that the city would slide into ruin if the NYPD wasn't able to summarily pat down hundreds of thousands of young men of color. Remember when our billionaire mayor told us that police officers would die if the police department wasn't allowed to keep violating New Yorkers' constitutional rights?

So how does it work? Can public officials truly be responsible for a sustained decrease in crime over period of more than two decades? Can crime's character be adequately disentangled from society?

It's a cliche to invoke former Commissioner Ray Kelly's comment to Time Magazine that taking credit for lower crime is "like trying to take credit for an eclipse." But that observation is useful if only to point out how many of our public servants ignore it.

"Commissioner Bratton and his team — and of course, all the men and women of the NYPD — deserve tremendous credit," the mayor said yesterday. "We can see with our own eyes, we can experience in our own lives a safer city and a city that is becoming more unified."

Today we have Manhattan DA Cy Vance, Jr. telling the Times that it's his "Moneyball approach to crime," whatever that means, and their "extreme collaboration" with the NYPD (for a taste of the tenor of the piece, here is Vance describing his time as a prosecutor during The Bad Old Days: "Every day was a scramble. We were learning things they didn’t teach in law school”).

One fact left largely unexplored during yesterday's announcement is that misdemeanor arrests are up. Way up: 190.5% since 1980, thanks in large part to Bratton's "Broken Windows" strategy.

Has crime declined because police make arrests for littering, or jumping a turnstile, or committing no crime at all?

A recent report found that 38.5% of all those misdemeanor arrests made in the city are dismissed at arraignment; prosecutors decline to pursue another 7% (in other municipalities this number is close to zero).

How many years will we wait for the press conference to acknowledge that perhaps more arrests doesn't necessarily mean a safer city?