A COUPLE of years ago, the gonzo television journalist Charlie LeDuff wanted to show people how impotent the police department of Detroit, a city then spiralling into bankruptcy and dysfunction, had become. So he visited a woman who had just called 911 to report a burglary at her house, and rolled film as they waited. To great comic effect, Mr LeDuff checked the house for intruders himself, then went to McDonald’s—twice—took a bath, and read a book to a child. The police finally showed up after four hours. Mr LeDuff’s viral video could just as well have been filmed in New Orleans. A recent joint investigation by The New Orleans Advocate and WWL-TV found that New Orleans police have taken an average of 79 minutes to respond to 911 calls so far this year. That figure has tripled since 2010. And while police usually come more quickly to priority calls, response times in those cases have doubled as well, to an average of 20 minutes.

With its persistent violent-crime problem, there are plenty of genuine emergencies to worry about in New Orleans. The city’s murder rate is always among the nation’s highest, and armed robberies have been on a steep upswing. They are not all happening in dark alleys. In August, gunmen hit a tony restaurant in New Orleans’ Uptown neighbourhood toward the end of dinner service, sending a collective shiver across the town’s moneyed elite. More than a dozen patrons were relieved of cash and valuables.

Police in that incident took 17 minutes to arrive—which sounded bad at the time, but as it turns out, is actually rather better than usual.

Other stories are scarier, if less widely known. Resident Sofia Froeba was unable to get police to respond at all to her call after she was carjacked and pistol-whipped into unconsciousness. It took two months and repeated visits to a precinct house for Ms Froeba to get police to even write a report.

Lindsay Nichols was even unluckier. When she called 911 to report a man threatening her with a gun, it took eight minutes for the operator to dispatch a cop, even though one was nearby. Hours later, her body was found in the trunk of a burned-out car; she had been fatally shot.

Ms Nichols's murder occurred in New Orleans East, a huge, unloved swath of the city whose residents often complain of being neglected by City Hall. When it comes to police alacrity, they definitely have a point: cops take two and a half hours to get to a typical call there, nearly twice the city average.

Indeed, things have got so bad in New Orleans that crime victims have often left the scene by the time officers get there. The proportion of calls that are classed “gone on arrival” or “unfounded” has doubled in recent years, to one in four. Cases marked that way get little or no followup; as a public-relations bonus, they’re not even counted as crimes.

How long is too long to wait for the police? There isn’t really an agreed-upon standard in America, although there does seem to be a consensus that the times in New Orleans (and Detroit) are too long—especially given the level of violence in both cities.

But apples-to-apples comparisons among cities can be tricky, in part because there are differences when it comes to which calls are categorized as emergencies. A report prepared for creditors as part of Detroit’s reorganization plan in 2013, for instance, says that Detroit cops were getting to non-emergency calls in an average time of 56 minutes that year. Oddly, Detroit’s cops were even slower—58 minutes average—in arriving at “priority” calls.

High-functioning cities, like New York, do much better on both ends: 9 minutes for a typical call, and about half that for priority calls. Dallas officials this year reported average response times of 22 minutes for non-emergency calls, and under 9 minutes for emergencies. For police departments around the country, meanwhile, the average response time is of 11 minutes, according to the Detroit report.

While Detroit’s dysfunction has been well-documented, New Orleans has in many ways been on an upswing in recent years, making its laggard response times more puzzling. Unlike Detroit, it population and tax base are both growing steadily.

The most obvious answer is a police department whose ranks of sworn officers have shrunk by about one-quarter since 2010, the year Mayor Mitch Landrieu took office.

As he often points out, Mr Landrieu inherited a large budget deficit from his feckless (and now imprisoned) predecessor, Ray Nagin, and one of the things he did to close the gap was to allow the NOPD to shrink through attrition.

But now Mr Landrieu—whose police chief, Michael Harrison, concedes the response time lag is a big problem—acknowledges it’s time to replenish the force. Something the mayor is less keen to admit is that building back to the level he and others want is likely to take many years.

The size of the NOPD may not be the only issue—after all, response times have been rising much faster than the ranks of officers have been thinning. The city’s inspector general has argued that it’s not the number of officers the department has as much as it’s the way they’re deployed. And some cops say that the strictures of a federal consent decree mandating reforms in the department is also having an effect. There are various new protocols to follow and paperwork requirements to meet.

Some of that is probably true, though cutting out the new red tape may not be the answer. A police department with such a troubled history has to make sure that it doesn’t cast aside standards simply to put more boots on the ground.