If you murder someone in America, there’s a nearly 40 percent chance you’ll get away with it. If you severely assault someone, there’s a 50 percent chance. And if you commit any other crime, there’s a good chance you’ll get away with that, too.

That’s the takeaway from the FBI’s latest data on crime in the US. The FBI put this data in a hideous, unreadable chart. (Then again, if I were law enforcement, I’d want to hide these figures.) Here, I offer a clearer version:

The figures show the “clearance rate,” the percentage of property and violent crimes that are resolved in an arrest or other means by police — essentially, cops’ solve rates for crime.

The numbers are bad across the board. For murder, the clearance rate is 61.6 percent. For aggravated assault, it’s 53.3 percent. For rape, 34.5 percent. For property crimes, it drops below 20 percent.

In short, police aren’t making arrests for the majority of crimes.

What’s worse, these numbers only tell part of the story. In some communities, the murder clearance rates, for example, drop even lower. Wesley Lowery, Kimbriell Kelly, and Steven Rich recently reported on that disparity for the Washington Post. In an analysis of killings over the past decade in 52 of the US’s largest cities, the Post found that “black victims, who accounted for the majority of homicides, were the least likely of any racial group to have their killings result in an arrest. ... While police arrested someone in 63 percent of the killings of white victims, they did so in just 47 percent of those with black victims.”

In some of the worst-off communities, David Kennedy, a criminologist at John Jay College, told Mother Jones in 2015, the clearance rate for murders and nonfatal shootings can fall even further — “down to single digits.”

The good news is the crime and murder rates fell in 2017, following two years of increases in violent crime and murder in particular. But the clearance rate numbers suggest that there is room for police to improve. In fact, the low clearance rates might be one thing that helps keep crime higher in the US than it would be otherwise.

To prevent more crime, police should do better

This is nothing new. The murder clearance rate has generally hovered around 60 percent for years. And the violent crime clearance rate has remained around 45 percent and the property crime clearance rate around the high teens, according to a Pew Research Center analysis.

This has dangerous consequences, contributing to what scholars call “legal cynicism.” When crimes go unpunished, people are more likely to think that the government — and particularly the police and criminal justice system — aren’t taking such acts very seriously. And that makes people distrust the police and justice system.

That not only makes people less likely to report crime, but it might lead to even more law-breaking. For one, if criminals are more likely to think they can get away with the acts, they’re more likely to commit them. And the lack of arrests keeps repeat offenders on the streets as well, free to commit more crime without consequence.

But there’s another piece to this too: If people don’t feel like police will protect them, they may be more likely to take the law into their own hands.

Consider a hypothetical murder that goes unsolved. If you believe that someone shot and killed a family member and may try to go after you next, and that police aren’t going to do anything about it, then you might be more likely to try to go after the shooter on your own to stop them.

Journalist Jill Leovy documented this phenomenon, with a focus on black communities, in her award-winning book Ghettoside (which, really, you should read). As she put it: “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.”

Leovy argues that this reflects a lack of resources going to solving murders, particularly in minority communities. Some of this is intentional, because, over the past few decades, police have favored approaches that they believe prevent crime, instead of solving crimes after they happen. (Indeed, there is good evidence that some proactive strategies, like hot spot policing and focused deterrence, do reduce crime. But these policies don’t have to be either-or; the police could solve and prevent crimes, as is generally expected of them.)

Community distrust also plays a role, since it makes it harder for police to get cooperating witnesses needed to solve murders. In this way, community distrust and poor crime solve rates feed into each other — people are less likely to cooperate with police when they feel unprotected by the law, and police are less able to protect people without cooperation. All of this together leads to fewer arrests, especially when black people, who are less likely to trust the police, are the victims.

On the other hand, some evidence indicates that police could do better if they put more resources toward solving crimes. A 2017 study by criminologist Anthony Braga looked at the Boston Police Department’s efforts to increase the murder clearance rate by dedicating more resources and technology to solving such killings.

The study found that Boston police raised the murder clearance rate from 47.1 percent before the changes (2007 through 2011) to 56.9 percent during the changes (2012 through 2014). In contrast, the national clearance rate remained stable during these time periods, while the rate for other Massachusetts police agencies actually declined. While the study couldn’t definitively link Boston’s improvement to the specific strategies the city’s police used, the research indicates that improvement really is possible, one way or another.

That suggests that police are generally doing much less than they could to investigate and solve the most serious crimes.

For more on what works to combat crime and violence, read Vox’s explainer.