Violence in Chicago is reaching epidemic proportions. In the first five months of 2016, someone was shot every 2¹/₂ hours and someone murdered every 14 hours, for a total of nearly 1,400 nonfatal shooting victims and 240 fatalities.

Over Memorial Day weekend, 69 people were shot, nearly one per hour, dwarfing the previous year’s tally of 53 shootings over the same period. The violence is spilling over from the city’s gang-infested South and West sides into the downtown business district; even Lake Shore Drive has seen drive-by shootings and robberies.

“I’ve been in Chicago all my life. It’s never been this bad. Mothers and grandchildren are scared to come out on their porch.” - Chicago resident

The growing mayhem is the result of Chicago police officers’ withdrawal from proactive enforcement, making the city a dramatic example of what I have called the “Ferguson effect.”

Since the fatal shooting of Michael Brown in Ferguson, Mo., in August 2014, the conceit that American policing is lethally racist has dominated the national airwaves and political discourse, from the White House on down.

In fact, this sentiment appears to be what fueled the slaying of five officers in Dallas after white cops shot black men in Baton Rouge, La., and Minnesota last week.

In response to this feeling, cops in minority neighborhoods in Chicago and other cities around the country are backing off pedestrian stops and public-order policing — and criminals are flourishing in the resulting vacuum.

Chicago mayor Rahm Emanuel warned in October 2015 that officers were going “fetal,” as shootings in the city skyrocketed. Residents of Chicago’s high-crime areas are paying the price.

Felicia Moore, a wiry middle-aged woman with tattoos on her face and the ravaged frame of a former drug addict, says: “I’ve been in Chicago all my life. It’s never been this bad. Mothers and grandchildren are scared to come out on their porch.”

Through the end of May, shooting incidents in Chicago were up 53 percent over the same period in 2015, which already had seen a significant increase over 2014. Compared with the first five months of 2014, shooting incidents in 2016 were up 86 percent. Shootings in May citywide averaged nearly 13 a day, a worrisome portent for summer.

Anti-police animus is nothing new in Chicago, of course. An Illinois state representative, Monique Davis, told a Detroit radio station in 2013 that people in her South Side community believed that the reason so few homicide cases were solved is that it was the police who were killing young black males. Davis later refused to repudiate her statement: “We can’t say that it is not happening.”

The “no-snitch” ethic of refusing to cooperate with the cops is the biggest impediment to solving crime, according to Chicago commanders. But the Black Lives Matter narrative about endemically racist cops has made the street dynamic much worse. A detective says: “From patrol to investigation, it’s almost an undoable job now. If I get out of my car, the guys get hostile right away and several people are taping [with cellphones].”

Bystanders and suspects try to tamper with crime scenes and aggressively interfere with investigations. Additional officers may be needed during an arrest to keep angry onlookers away. “It’s very dangerous out there now,” a detective tells me.

In March 2016, then-Chief of Patrol (now Superintendent) Eddie Johnson decried what he called the “string of violent attacks against the police” after an off-duty officer was shot by a felon who had ordered him on the ground after robbing him. The previous week, three officers were shot during a drug investigation.

This volatile policing environment now exists in urban areas across the country. But Chicago officers face two additional challenges: a new oversight regime for pedestrian stops; and the fallout from an officer’s killing of Laquan McDonald in October 2014.

In March 2015, the ACLU of Illinois accused the Chicago Police Department of engaging in racially biased stops, locally called “investigatory stops,” because its stop rate did not match population ratios.

This by-now drearily familiar and ludicrously inadequate benchmarking methodology ignores the incidence of crime.

In 2014, blacks in Chicago made up 79 percent of all known nonfatal-shooting suspects, 85 percent of all known robbery suspects and 77 percent of all known murder suspects, according to police department data.

Whites were 1 percent of known nonfatal shootings suspects in 2014, 2.5 percent of known robbery suspects, and 5 percent of known murder suspects, the latter number composed disproportionately of domestic homicides. Whites are nearly absent, in other words, among violent street criminals — precisely whom proactive policing aims to deter. Whites are actually over-stopped compared with their involvement in street crime.

Despite the groundlessness of the ACLU’s racial-bias charges, then–police Superintendent Garry McCarthy and the city’s corporation counsel signed an agreement in August 2015 allowing the ACLU to review all future stops made by the department. The agreement also created an independent monitor for police stops. “Why McCarthy agreed to put the ACLU in charge is beyond us,” says a homicide detective.

On January 1, 2016, the police department rolled out a new form for documenting investigatory stops, developed to meet ACLU demands. The new form, traditionally called a contact card, was two pages long and contained a whopping 70 fields of information to be filled out, including three narrative sections. The new contact card took 30 minutes to complete. Every contact card is forwarded to the ACLU.

Stops dropped nearly 90 percent in the first quarter of 2016. Detectives had long relied on the information contained in contact cards to solve crimes.

When 15-year-old Hadiya Pendleton was killed in January 2013, days after performing with her high-school band in President Obama’s second inaugural, investigators identified the occupants of the getaway car through descriptions of the vehicle in previous contact cards. Now, however, crime sleuths have almost nothing to go on.

Criminals have become emboldened by the police disengagement. “Gangbangers now realize that no one will stop them,” says a former high-ranking police official. And people who wouldn’t have carried a gun before are now armed, a South Side officer says. The solution, according to officers, is straightforward: “If tomorrow, we still had to fill out the new forms, but they no longer went to the ACLU, stops would increase,” a detective claims.

But a more profound pall hangs over the department because of a shockingly unjustified police homicide and the missteps of top brass and the mayor in handling it.

On the night of Oct. 20, 2014, a report went out over the police radio that someone was breaking into cars in a trucking yard in the southwest neighborhood of Archer Heights; the vandal had threatened the 911 caller with a knife.

Two officers found 17-year-old Laquan McDonald a block away; he punctured a tire on their squad car and struck its windshield with his 3-inch blade. The cops trailed McDonald, who was high on PCP, for nearly a half-mile while waiting for backup units with a Taser. Two additional patrol cars pulled up as McDonald strode along the middle of Pulaski Road, energetically swinging his right arm, knife in hand. One car parked behind him; its dashboard camera recorded the subsequent events. The other car stopped about 30 yards ahead.

The officers in that forward vehicle jumped out, guns pointed at McDonald, commanding him to drop the knife. Less than 10 seconds after exiting, Officer Jason Van Dyke began shooting.

The shooting, pitiable to watch, represented a catastrophic failure of tactics and judgment.

And what followed the homicide was almost as shocking. Five officers at the scene all told variants of the same tale in their written reports: that McDonald had been advancing toward Van Dyke, aggressively raising his knife as if to attack. None of those claims is borne out by the video.

Still, a police-union spokesman at the scene of the killing told reporters that McDonald had been threatening Van Dyke. The police department press release a few hours later essentially echoed that account, stating that McDonald continued to approach the officers after being warned.

Superintendent McCarthy viewed the video the next day, without retracting the department’s press release, explaining later that he was too busy trying to learn what had happened. From then on out, officials made no effort to countermand the McDonald attack narrative.

McCarthy immediately stripped Van Dyke of his police powers and forwarded the case to the civilian board that reviews police shootings, the Independent Police Review Authority (IPRA).

The case also went to the Cook County state attorney’s office, the US Attorney’s Office and the FBI.

In April, the mayor’s corporation counsel, Stephen Patton, attained city council approval for a $5 million settlement with the McDonald family, conditioned on the continued non-release of the video.

Later that month, the detectives’ bureau cleared and closed the case, astoundingly concluding that the “recovered in-car camera video was . . . consistent with the accounts of the witnesses” and that “Van Dyke’s use of deadly force was within bounds of CPD guidelines.”

By then, the Chicago press was clamoring for the video’s release, but it was not until Nov. 24, 2015, that the video came out, under a judge’s order. The reaction was understandably explosive; weeks of angry protests denouncing alleged police racism and brutality followed.

The Cook County state attorney announced first-degree murder charges against Officer Van Dyke on the day that the McDonald video was released.

Mayor Emanuel fired McCarthy a week later and appointed the Police Accountability Task Force, dominated by critics of the police.

That task force issued a report in April 2016, claiming that the Chicago Police Department is shot through with “racism.”

Emanuel is now genuflecting to the city’s activists. He has adopted many of the report’s most sweeping recommendations, including the appointment of a costly and unnecessary inspector general for the department (that will come on top of the independent monitor for investigatory stops), the replacement of the IPRA with a new entity, the Civilian Police Investigative Agency, and the creation of the Community Safety Oversight Board. All these additional layers of oversight will only complicate chains of command and further discourage proactive policing.

Allowing a fabrication about a very bad shooting to stand, especially during the current era of fevered antipolice sentiment, is guaranteed to amplify the demagoguery against the police.

Emanuel has praised himself for being the first Chicago mayor to acknowledge an alleged police code of silence, but he knew about the shooting, and his aides had seen the video early on. It is irresponsible for Emanuel to scapegoat McCarthy when his own administration also failed to set the record straight.

Allowing a fabrication about a very bad shooting to stand, especially during the current era of fevered antipolice sentiment, is guaranteed to amplify the demagoguery against the police.

The damage to the Chicago police and to policing nationally from the mishandling of the McDonald homicide is incalculable. The episode can now be invoked to confirm every false generalization about the police peddled by the Black Lives Matter movement. Yet the shooting was a tragic aberration, not the norm.

The vast majority of officers today observe the law and are dedicated to serving the community; what they need is more tactical training, adequate staffing and equipment and better leadership from an ingrown, highly political management cadre. As for the alleged blue wall, or code, of silence, it is hard in any department to crack the defensive solidarity among officers, who feel that they are facing an uncomprehending and often hostile world.

Even now, a few of the officers I spoke with will not pass judgment on the McDonald homicide, on the grounds that they were not there. Such solidarity is understandable, but commanders need to stress that when it results in distorting the truth, not only will the officer be severely punished; he is also making today’s anti-cop environment all the worse.

Heather Mac Donald is the author of the just released “War on Cops” (Encounter Books). This piece has been adapted from Summer City Journal.