The Facebook Live video, recorded on Tuesday, opened with what looked like a happy family enjoying a car ride, singing along to a song by rapper Chief Keef as it played on the radio.

Suddenly, the mood changed: Loud bangs popped in the background and the woman screamed — “Please! No!” — in pain. When the hail of bullets calmed, a 2-year-old boy was fatally wounded, his 20-year-old aunt was seriously injured, and her 26-year-old boyfriend was dead.

The details were exceptionally horrific — a 2-year-old, after all, was shot and killed, and his pregnant aunt, whose unborn baby survived, was wounded. But the overall story has become all too familiar for Chicago — the apparent result of yet another targeted shooting against a documented gang member, the boyfriend.

It happened hundreds of times in Chicago throughout 2016: Someone picked up a gun and shot and killed another human being. By the end of the year, the death toll of this kind of violence reached 762 homicides — adding up to hundreds of fathers and mothers, brothers and sisters, and sons and daughters who were killed in violence largely rooted in interpersonal conflicts. The final death toll was up 57 percent from 2015, and Chicago contributed to about half of last year’s rise in murders among major US cities.

Seeing violence like this, President Donald Trump has said he wants to do something about it. In the past few months, Trump has tweeted that he will “send in the Feds” and offer “Federal help” to Chicago if local and state officials don’t get the recent wave of violence under control.

Some local officials quickly condemned Trump’s rhetoric. Alderman Raymond Lopez said, “We don’t need tanks rolling down Ashland or Archer.” Others, like Mayor Rahm Emanuel, acknowledged a need for help: “I would welcome … federal participation in working with law enforcement to deal with guns and gangs.” Emanuel later reiterated this call in a meeting with Attorney General Jeff Sessions.

So what did Trump mean when he said he wants to “send in the Feds” and “Federal help” to Chicago? What could Trump possibly do?

Getting no concrete answers from the White House about this, I turned to criminal justice experts who have spent their careers in law enforcement and studying policing for some answers. I approached them with a simple question: Given that we know little about Trump’s actual proposal here, what could he be suggesting? And what are some of the good and bad ideas he could try in this area?

Experts typically said they interpreted Trump’s comments to suggest a “tough on crime” approach — sending in the National Guard or federal law enforcement agents for a crackdown on crime. This would be in line with the kind of approach Trump based much of his campaign on, with a focus on “tough” policies like longer prison sentences and harsher police tactics. (Asked by Bill O’Reilly how he would solve Chicago’s problem, Trump once frankly responded, “By being very much tougher than they are right now.”)

Yet this approach, experts said, wouldn’t accomplish much — and it could in fact make things worse if it further inflames community-police relations, which are a big source of the violence seen in the city today. Instead of the “tough” approach, they called for a more targeted strategy that would focus on the few individuals in Chicago that drive most of the violence.

But before we get to Trump’s potential plan and how federal aid could actually help Chicago, it’s important to first understand how the city got to a point where the US president is now demanding something be done.

Putting Chicago’s violence in context

While 2016 was a particularly bad year for Chicago, it still wasn’t the most violent year in Chicago’s history. The final death toll of 762 homicides in 2016 came below the toll of 796 in 1996. That somewhat reflects a nationwide trend toward fewer crimes and murder: Between 1990 and 2015, the nationwide murder rate dropped by about half.

Chicago is also far from the most violent city in America. An analysis by the Trace put Chicago’s murder rate at 27.9 per 100,000 residents. Many other cities, particularly in the Midwest and Rust Belt, fared worse, including St. Louis (59.3), Baltimore (51.2), and Detroit (45.2).

And much of Trump’s focus on Chicago is likely just a racist dog whistle, as Jenée Desmond-Harris explained for Vox. Khadijah Costley White, an assistant professor in the department of journalism and media studies at Rutgers University, told Desmond-Harris, “For Trump, Chicago has become symbolic for unchecked and seemingly irrational black violence, which of course is implicitly perceived as an ongoing threat to the safety of white people.”

But Chicago is the third most populous city in the country — after New York City and Los Angeles. That puts it in the national spotlight in a way that smaller cities may not be.

And even if it’s not the most violent place in America, Chicago still provides a case study for what’s going wrong with crime and policing in America and how to fix those issues. That’s something criminal justice experts told me again and again: Many of the problems in Chicago are actually present across the entire country, particularly in the Midwest, Rust Belt, and the other violent cities that lie outside those regions.

How Chicago got to this point

The experts I spoke with, some of whom had worked in Chicago in some capacity, all agreed on a few big reasons that explain why the city is so notoriously violent.

First, Chicago is extremely segregated. During the Great Migration, as many black Americans abandoned the Jim Crow South for the North, Chicago became a major destination. But the predominantly white power base wasn’t receptive to the sudden change. They instituted all sorts of barriers — such as restrictive covenants, redlining, blockbusting, and steering — that, along with public housing policies, pushed mostly black residents into impoverished, crime-ridden neighborhoods. (For a deeper dive into Chicago’s segregation, read Ta-Nehisi Coates’s “The Case for Reparations.”)

This created a situation in which black Chicagoans were left to struggle in places where they had little chance of establishing a safe, prosperous life. The result is Chicago has a few predominantly black neighborhoods with high levels of crime and few resources and little government attention to combat that crime.

Consider the finding of a New York Times analysis comparing segregation in New York City and Chicago: Less than 1 percent of New York City’s population lives in an area where everyone is of the same race, and most of these segregated places are white. Meanwhile, 12 percent of the black population in Chicago lives in a Census block group that is entirely black.

At the same time, New York City is one of the safest cities in the country, with a homicide rate of around 4 per 100,000 residents in 2016. Chicago’s murder rate, by contrast, was nearly 28 per 100,000 people in the same year.

“Chicago is a very segregated city in ways New York is not,” John Roman, a criminal justice expert at NORC at the University of Chicago, told me. “That segregation, that isolation is a recipe for more crime and more violence when there are other inputs that spark things.”

Second, there’s the problem of guns. Chicago has fairly strict gun laws, at least relative to the rest of the US. But its neighbors — particularly the rest of Illinois and Indiana — aren’t nearly as strict.

Consider Indiana, which is a few minutes’ drive away for many Chicagoans. Chicago requires a Firearm Owner Identification card, background check, three-day waiting period, and documentation for all firearm sales. But Indiana doesn’t require any of this for purchases between two private individuals (including those at gun shows and those who meet through the internet), allowing even someone with a criminal record to buy a firearm without passing a background check or submitting paperwork recording the sale.

So someone from Chicago can drive across the border — to Indiana or to other places with lax gun laws — and buy a gun without the legal hurdles he would face at home. Then that person can resell or give guns to others in Chicago or keep them, leaving no paper trail behind. (This is illegal trafficking under federal law, but Indiana’s lax laws and enforcement — particularly the lack of a paper trail — make it nearly impossible to catch someone until a gun is used in a crime.)

The result: A lot of criminals get their guns from Indiana. According to a 2014 report from the Chicago Police Department, nearly 60 percent of the guns in crime scenes that were recovered and traced between 2009 and 2013 came from outside the state. About 19 percent came from Indiana — making it the most common state of origin for guns besides Illinois.

The easy access to guns, despite Chicago’s relatively tough gun laws, leads to more gun deaths. Research has consistently found this link between more guns and more gun deaths to be true — not just for homicides, but also suicides, domestic violence, and violence against police.

The statistics show Chicago has an outsized gun problem: An analysis by the University of Chicago Crime Lab found that while Chicago has a similar rate of nongun homicides as other big cities in the US, it has far more gun homicides — helping explain why it’s one of the most violent cities in America.

“I think the story is mainly about firearms,” Roman said, again drawing on a comparison between New York and Chicago. “Chicago traffics in weapons in ways New York doesn’t simply because New York is more physically isolated from places where gun purchase and movement is easy compared to Chicago.”

Third and finally, the Chicago Police Department has huge problems with trust. The issue here may not be much worse than other American cities, but it’s still fairly bad.

The US Justice Department’s recent investigation into the Chicago Police Department concluded, for example, that overly aggressive, frequently outright racist policing has led to a “breakdown in community trust.” It highlighted several problems with Chicago police, from the use of “stop and frisk” (which was found unconstitutional in New York because it was deployed in a racially biased way) to a lack of accountability for officer misconduct that ranged from the public use of racial slurs to excessive force. The Justice Department argued that the Chicago Police Department must rebuild trust with the community to help end the bloodshed.

Combined, these problems created a powder keg in Chicago: a climate in which people are desperate, have easy access to guns, and don’t feel they can trust the police when problems arise. So when the next wave of retaliatory violence came around, the city was already caught in an unmanageable situation. And the police shooting of Laquan McDonald — in which police initially said that a black 17-year-old charged at an officer before the cop shot him, only for video to show the teenager wasn’t a threat — made things even worse, further antagonizing distrust in the police and, as a result, limiting the police’s ability to control the violence.

Distrust in the police is very bad for public safety

For many Chicagoans, McDonald’s death proved the standard criticism of police: Cops let violence continue largely unabated in black neighborhoods, generally ignoring the problems that most require police to solve. Chicago’s murder clearance rate, for example, is around 30 percent. And when cops do police black Americans, it’s usually in a manner that’s far too aggressive and typically for relatively minor crimes, like traffic violations or drugs.

The distrust this dual problem fosters leads to more violence: If people feel like they can’t trust law enforcement, they’re more likely to take matters into their own hands to solve interpersonal disputes.

A 2016 study, from sociologists Matthew Desmond of Harvard, Andrew Papachristos of Yale, and David Kirk of Oxford, looked at the effects of 911 calls in Milwaukee after incidents of police brutality hit the news.

They found that after the 2004 police beating of Frank Jude, 17 percent (22,200) fewer 911 calls were made in the following year compared with the number of calls that would have been made had the Jude beating never happened. More than half of the effect came from fewer calls in black neighborhoods. And the effect persisted for more than a year, even after the officers involved in the beating were punished. Researchers found similar impacts on local 911 calls after other high-profile incidents of police violence.

But crime still happened in these neighborhoods. Indeed, as 911 calls dropped, researchers also found a rise in homicides. They note that “the spring and summer that followed Jude’s story were the deadliest in the seven years observed in our study.”

That suggests that people were simply dealing with crime themselves. And although the researchers couldn’t definitively prove it, that might mean civilians took to their own — sometimes violent — means to protect themselves when they couldn’t trust police to stop crime and violence.

“An important implication of this finding is that publicized cases of police violence not only threaten the legitimacy and reputation of law enforcement,” the researchers write, “they also — by driving down 911 calls — thwart the suppression of law breaking, obstruct the application of justice, and ultimately make cities as a whole, and the black community in particular, less safe.”

This phenomenon — an example of what’s known as “legal cynicism” — shouldn’t be too surprising. As journalist Jill Leovy wrote in her groundbreaking book Ghettoside, “Take a bunch of teenage boys from the whitest, safest suburb in America and plunk them down in a place where their friends are murdered and they are constantly attacked and threatened. Signal that no one cares, and fail to solve murders. Limit their options for escape. Then see what happens.”

A heavy-handed police approach would likely make things worse

In this environment, it’s not really surprising that a president would want to act. Still, it’s hard to say what Trump meant when he said that he would “send in the Feds” or give “Federal help” to Chicago in his tweets. The White House hasn’t responded to questions asking for clarification and whether a more specific anti-crime plan is in the works.

But given the president’s history as someone who ran on a “law and order” platform, criminal justice experts said Trump is likely referring to two possible “tough on crime” approaches: Either sending in the National Guard to Chicago or pushing for a federal law enforcement “surge” in the city.

The possibility of sending in the National Guard is so ridiculous that experts didn’t seem to know what to make of it. It’s unclear what the troops would even do; they don’t have training for policing, and it’s not like there’s widespread violence, such as riots or actual warfare, that soldiers are typically called in to deal with.

“It’s not going to reduce crime,” Richard Rosenfeld, a criminologist at the University of Missouri–St. Louis, told me. “And it’s simply anathema to our tradition of civilian crime control and local crime control in the United States.”

The other possibility is a federal law enforcement surge, in which federal prosecutors and agents are deployed to Chicago to work with local police to reduce crime. This kind of surge has been done frequently in the past. In fact, the feds deployed a surge in Chicago in 2014. Typically, they involve putting together a task force, setting up stings and buys, and then getting a bunch of convictions.

But experts agree these surges are too unfocused and too brief to make a long-term dent in crime — and the federal government doesn’t have the resources or will to sustain a surge for very long.

“It tends not to work,” Thomas Abt, a criminal justice expert at Harvard University, told me. “And if it works, it tends to work temporarily. You have this temporary lull when these guys are taken off the street, but then there’s nothing done to address the underlying conditions.” Abt added that this lull could even lead to more violence, since research shows that crackdowns on illegal drug markets often lead to power vacuums that groups then fight to fill.

Police leaders also don’t think much of federal law enforcement surges. For a recent report by the Police Foundation and the Major Cities Chiefs Association, police leaders around the country were asked how federal assistance could help combat crime. With just 19 percent calling federal surges “very useful,” they were the least popular option. Police leaders, however, strongly supported federal resources for ballistic imaging (94 percent called it “very useful”) and gun tracing (83 percent), as well as grant funding (77 percent) and support — whether through funding or training — for “evidence-based strategies and programs” (66 percent).

The consequence of a federal surge could go from ineffective to bad if Trump couples such a move with other “tough on crime” policing tactics he has advocated for in the past, like the controversial “stop and frisk” strategy that a court struck down in New York City because it was used to target minority Americans. While the research shows that tactics like “stop and frisk” have little to no effect on crime, these approaches lead to more community distrust because they’re seen as racially biased.

Experts warned that these kinds of aggressive tactics can be counterproductive — and actually lead to more crime. If part of the problem is that the community distrusts the police, a larger, more heavy-handed police presence — especially one that involves a National Guard occupation — will only make problems worse.

But experts argue there’s a better way for Trump and the federal government to fight crime.

How the feds could help Chicago (and other violence-stricken cities)

If there’s one way to describe what’s gone wrong with modern American policing, it’s that policing is typically approached with a shotgun when a scalpel is a much better fit.

Since the 1980s led to a militarized, “tough on crime” approach to policing, the tactics have usually involved sweeping approaches that target entire populations — “stop and frisk” of entire neighborhoods, widespread raids, and so on.

But violence is very concentrated in American cities. Chicago is no exception. As a big investigation by the Guardian recently found, “13% of census tracts in Chicago saw multiple gun murders in 2015, and these tracts were responsible for 65% of the city’s gun homicides.” And as Abt previously wrote for Vox, “In most cities across the nation, 3 to 5 percent of city blocks account for 50 to 75 percent of all shootings and killings, with 1 percent of a city’s population responsible for 50 to 60 percent of all homicides.”

That’s why criminal justice experts say the best approach is one that is targeted — going after “hot spots” with a sharp focus on certain blocks, streets, and even people. To this end, experts have developed policing strategies known as “hot-spot policing” and “focused deterrence” to do just what they’re asking.

Focused deterrence has particular promise behind it. Through this strategy, police work with the community to target specific individuals at a very high risk of violence. They directly and clearly signal to these individuals that they have two options: quit doing bad things and the community will offer resources, such as job training, to help you, or you absolutely will be arrested. In doing this, the police and community can deter individuals responsible for most of the crime in their city from acting out, and maybe even help these individuals lead more productive lives.

The research says it works: Study after study backs up focused deterrence, and the method got much of the credit for the “Boston miracle” that saw the city’s violent crime rate drop by 79 percent in the 1990s.

The federal government, if Trump was willing to, could directly encourage this style of policing. “I would like to see the feds help the locals with targeted enforcement, funding for intervention and prevention, and also to help them get smart on crime using evidence and data,” Abt said. “We need to help locals focus on those people, places, and behaviors that cause the great majority of crime and violence in American cities.”

Unfortunately, federal spending tends to go to antiquated styles of policing, including dragnet programs that finance broad, unfocused crackdowns on low-level offenses and vague “community policing” mandates with little oversight. Consider, for example, that Chicago has been receiving federal aid for years to keep more cops on the force for “community policing,” yet a Justice Department report just uncovered sweeping abuses that created a climate of distrust between the community and police.

Federal programs could be tweaked to remedy this. Not only could they encourage more evidence-based types of policing, but they could offer a sustained investment over many years instead of the drop-in-drop-out approach of federal law enforcement surges and loosely funded pilot programs.

“The question is how would those additional officers be put to best use. They would be put to best use … primarily in highly focused strategy that is focusing on the so-called hot places, the places where violence is most highly concentrated in Chicago, and the hot people in those places,” Rosenfeld of the University of Missouri–St. Louis said. “There’s not a police department in the country that couldn’t use more officers doing that kind of thing.”

But, Rosenfeld added, “If they had only the vaguest plan for how the officers would be deployed, it’s just doing more of the same, and the same hasn’t been all that effective recently.”

This is critical work: Police, after all, are the most public face of government. They are the branch of government that almost all Americans will interact with at one point or another. If Americans can’t trust them, they are going to question the legitimacy of a lot of what government does — and that legal cynicism can contribute to more crime.

Federal help could also go to community-based programs like Cure Violence, which sells itself as treating violence “like a contagious disease.” The program establishes a group of local “interrupters” with close ties to a neighborhood, who can then identify residents at immediate risk of violence and intervene — through mediation and by leveraging community resources — to prevent escalation. The model has been effective, with a 2009 study by researchers Wesley Skogan, Susan Hartnett, Natalie Bump, and Jill Dubois linking it to larger drops in violence than were otherwise seen in Chicago neighborhoods.

But the program has lost funding in recent years — leading the group to publish a report in September that showed a correlation between reduced funding to it and increased killings in Chicago. While some experts are skeptical that the group’s efforts have that much sway over the city’s overall gun violence, there was general agreement that efforts like this — if they get adequate funding — can help combat gun violence as part of a comprehensive plan along with broader police reforms.

There are also some ways that Trump could actually “send in the Feds” to Chicago to good effect, particularly if he takes enforcing federal gun laws more seriously.

“If sending in the feds means strengthening the relationship with the ATF, which does try to disrupt firearm markets and tries to impede the movement of firearms from low-regulation into higher-regulation states, that’s all for the good,” Rosenfeld said.

Then there’s other kinds of federal help that could help — such as funding for better schools, community health care programs, and the reintegration of schools and neighborhoods, all of which could aid with the underlying problems in Chicago. But experts cautioned that these kinds of policies would only help in the long term, not the immediate crisis of violence that Chicago is facing right now.

Of course, none of this is what Trump seems to be looking for; his tweets and history have suggested a far more aggressive, less reform-minded approach toward police and the criminal justice system in general. And his solutions could make the problem worse.

Watch: America’s gun problem, explained in 18 charts