But yesterday, the Police Department shared data showing that reported shootings, robberies and some other serious crimes increased last month compared with January 2019.

“The broad direction in January causes us real concern,” Mayor de Blasio said at a news conference.

The numbers announced yesterday, of course, were just a snapshot. An array of policy experts agree that meaningful trends cannot be seen in one month of crime data. (And, in fact, murder was down for the month.)

Still, New York’s police commissioner, Dermot Shea, quickly blamed the state’s new bail law for the rise last month. The law, which went into effect on Jan. 1, eliminates cash bail for most criminal defendants and allows them to stay free while their cases are pending.

[Spike in crime inflames debate over bail law.]

According to Police Department data, “precipitous increases in crimes like robberies, shootings and auto thefts drove a 16.9 percent increase in overall crime last month compared to January 2019,” my colleagues Ashley Southall and Jesse McKinley reported.

The reaction

Mr. de Blasio tried to assuage fears. “New York City is unquestionably the safest big city in America,” he said. The Police Department is “the finest police force in this country,” with a track record of reducing crime.