A really boring way to solve more serious violent crimes

Assign more detectives; give them more time

(Suzanne Kreiter/The Boston Globe via Getty Images)

Back at the beginning of August, Conor Friedersdorf wrote an Atlantic column arguing that police reformers had gone down a dead-end with “defund” and proposing instead that a worthy goal would be to try to actually solve murders — noting, in particular, the huge disparity in clearance rates based on the race of the murder victim.

Jamelle Bouie, seemingly in response to Friedersdorf, quipped that “a police department that largely devoted its resources to preventing and solving violent crime would look nothing like any currently existing American police department in terms of structure, personnel or training.”

It’s true that a clear orientation toward the prevention and solving of serious crimes would in fact be a significant shift in the culture of policing, but I don’t think the cross-sectional or experimental evidence supports the idea that dramatic cultural shifts and mass purges are the only ways to improve on this front. Rather, the most compelling evidence points toward relatively modest shifts in emphasis and resources, including hiring more investigators and asking officers to accept less job security in exchange for higher starting salaries, which would result in meaningful progress.

And of course, these shifts would require more money, not less. But I think that meaningful progress could be the start of a larger and more significant cultural shift.

Homicide clearance rates vary significantly

One question we can ask is whether low homicide clearance rates are a constant of American policing or an area where we see variation. In other words, when you ask a department to achieve a higher clearance rate, are you saying “be more like this other department over here,” or are you saying “be like something totally outside the experience of American policing”? And I think the numbers support the former.

The data available from the Murder Accountability Project tells us that in 2019, American police departments solved 58% of all reported homicides.

That is a low number. It also masks considerable variation. In Indiana, they solved 39% of murders, compared to 90% in Maine.

Maybe the sky-high Maine clearance rate just shows that we have a problem with urban policing. There are basically no cities in Maine, nor is there much racial diversity, so maybe policing works fine when white cops are patrolling white communities; it just totally breaks down in the face of urban issues. But if you compare Indiana to other Great Lakes states, it still looks really bad:

• Ohio solved 44% of murders.

• Michigan solved 57% of murders.

• Wisconsin solved 77% of murders.

Zooming in, Milwaukee County solved 64% of murders; the City of Milwaukee solved 62%. An urban police department working in a midwestern city with its share of problems beat the state averages in Indiana, Michigan, and Ohio.

But even within Ohio, Franklin County (Columbus) solved 64% of murders compared to just 44% in Cincinatti’s Hamilton County and only 28% (!!) in Cuyahoga County. In Detroit, they solved 51%, and Las Vegas boasted an impressive 87% homicide clearance rate that year.

Clearly, some American police departments warrant praise for their crime-solving adeptness — whatever their other problems may be — while other departments deserve to be singled out for criticism (even while acknowledging that there are structural features that make their work difficult). Getting the Clevelands and Indianapolises of the world up to Detroit and Milwaukee levels of murder solving is not going to eliminate all problems in American public safety, but it’s a worthy aspiration!

Interlude — a defense of preventative policing

Before diving deeper into this, I do think it’s worth explicitly saying that while I do think America should try harder to solve murders, I reject the idea that murder solving is the only legitimate mode of policing. In fact, in the early days of the defund fad, this was a big talking point — most police officers aren’t detectives solving serious crimes, and most departments aren’t very good at solving those crimes.

That’s entirely true, but what the standard “police walking around and being present” accomplishes is preventing crimes from happening. I won’t rehash all the data on that now, but here are two pieces I wrote for Vox on it.

I’d also note that the other big manpower drain on police departments is just sending cars out to respond to various calls. This is on average a fairly low-value/high-cost thing to be doing. But it also seems a little bit inescapable. If a person calls the police and says that they believe a situation requires the presence of a police officer, is the department really going to tell them no, even if many of the incidents do turn out to be fairly minor disturbances or someone needing a police report for a car break-in?

I think the shoplifting situation in San Francisco is a reminder that you need to be careful about how you handle minor infractions. California voters who worried about mass incarceration voted to turn shoplifting offenses under $950 into misdemeanors based on the logic that small-scale shoplifting just isn’t that big of a deal. And that’s true, it’s not! But what appears to have happened in the Bay Area is that the lifting of punishments for a minor crime encouraged bigger players to get involved in organized theft rings that shoplift on large scale and move the stolen goods. So now businesses are reducing hours (which is going to mean fewer jobs and probably more crime), and eventually, you’re probably going to end up with criminal syndicates at war with each other.

To me, the difference between sense and nonsense here goes back to George Floyd. I think it’s bad that he was murdered by officers after being arrested for passing a counterfeit $20. But some people seem to think it’s bad that he was arrested for passing a counterfeit $20. I obviously agree that this crime is not the end of the world. But if you didn’t punish counterfeiting, you’d get a lot more counterfeiting, and that would be a serious problem. The solution here is to not give up on preventative policing but to punish cops who abuse their power.

Solving serious violent crimes: What we know

Now back to solving crimes! The most effective deterrent to serious crime is one that involves humane, reasonable, and ideally rehabilitative punishments coupled with a high likelihood that you will be punished if you commit a crime. Especially if you’re inclined to think that the American penal system is too cruel, it is essential to try to catch a larger share of perpetrators.

And I would say that there are two main things we know about catching criminals. One is that it’s pretty hard and overall clearance rates are low. The other is that effort matters, and police departments are more likely to clear a case when they try hard to clear the case.

That sounds obvious, but it’s worth checking the research. Conventional wisdom among police officials (and apparently television executives) is that there is a magic “first 48 hours” when you are likely to solve a crime, after which it becomes basically impossible. This does not appear to be true. Instead, as crime statistician Jeff Asher recounts by citing a study of murders in Phoenix, you’re more likely to solve a murder when you assign more officers to investigate it.

The witnesses thing is out of the police department’s hands in the short-term (though more later on the longer term), but the quantity of investigative resources is not.

A very telling study out of Boston looked at why the Boston PD was so much more likely to solve murder cases than non-fatal shooting cases. After all, the underlying differences between a shooting that the victim survives and one in which the victim dies don’t really seem all that relevant from an investigative perspective. If anything, you might think it would be easier to solve non-fatal shootings since you have a living victim who can, in many cases, be a witness.

Part of the answer is that homicide is a more serious crime than “shot a guy but he lived,” so they invested more detective hours in trying to solve the homicides. Philip Cook, Anthony Braga, Brandon Turchan, and Lisa Barao looked at how this plays out in practice and found that for the first two days, the department deploys similar amounts of manpower whether the shooting is fatal or not. But if it’s non-fatal, the investigation ends after day two, while for murders, they keep working the case. And while about half of all cleared homicides are solved within that two-day window, the other half is solved through prolonged investigation. Inside that window, fatal and non-fatal shootings are solved at the same rate. But fatal shootings are twice as likely to be solved overall because of the value of continued investigation.

Both of those studies have been kicking around for years, and if it were up to me, we would have funded follow-up research in two dozen other cities. But I guess nobody is interested enough in this question to pursue it. Regardless, I think “detectives are more likely to solve a case if there are more detectives and they are given more time” has enough background plausibility that we should probably accept it. The key to clearing more violent crimes is to hire more investigators — both to investigate homicides more intensively and also to investigate non-fatal shootings more intensively. The shooters, after all, don’t know ex-ante whether they are going to kill their victims or not. To deter gun murders, you want to deter gunfire in general.

Fund the detectives

To make a long story short, it seems like a good way to increase the clearance rate for serious violent crimes would be to hire more detectives.

The typical city could, if it had more detectives available, investigate non-fatal shootings as rigorously as it investigates gun homicides, and it would end up solving a much higher share of non-fatal shootings. It’s less clear how many more murders could be solved with more detective hours of work, but the answer is “more than zero.” The key would be to continue prioritizing this as (hopefully) the incidence of shootings falls. Then you could either solve an even higher share of shootings, or else you could start increasing the investigation of robberies, burglaries, and other crimes.

From what we can tell, this works within the confines of the existing structures and cultures of policing. Changing those things might be desirable, but it’s not necessary to improve this aspect of policing.

Now, does that mean we should take random beat cops off the street and tell them to go solve murders instead, creating a win-win for skeptics of the policing status quo?

I’m a little skeptical:

• Detective work is hard, and lowering the bar for becoming a detective could undermine the whole effort.

• If some of today’s police officers are engaged in misconduct, the answer is to fire them, not to make them detectives.

• Preventative policing via patrol is effective at deterring shootings and serious crimes. We want to solve a large share of a small number of serious violent crimes, not solve a large share of a large number of serious violent crimes.

We also need to weaken police unions and, as Adam Serwer says, subject policing to democratic control. And just as has worked with teachers in D.C., we need to be willing to pay more money and hold people to a higher bar for performance.

But within those parameters, both preventative and investigative policing are useful. Of course other things are also useful, too. Cities should have nice parks and good buses and all kinds of public services. Any given city may face some difficult political tradeoffs over exactly what to invest in. But my basic view is that the United States of America is a low-tax country that underinvests in all kinds of public services. One should not embrace an austerity mentality which holds that the only way to hire more detectives is to fire beat cops or that the only way to hire more librarians is to fire detectives.

Detect for America

We should also reexamine police officer career trajectories.

The military has separate entry points and career paths for enlisted troops and officers than a separate group of warrant officers with specialized skills. Police departments have a lot of military-esque attributes but generally operate on a different principle where everyone starts out in the same place and promotions follow from there. And police departments employ civilians to do various things, but those specialists are not police officers. This is, again, different from the military, where an Army doctor follows a different career path from a non-doctor but is still definitely an Army officer with a uniform and a rank and the whole deal.

I think it’s possible that the best way to expand the investigator workforce would be to create a special career track for people to start as trainee detectives and do a whole career in investigations rather than in preventative policing. It’s a different set of skills, and it probably appeals to a somewhat different group of people.

Dylan Matthews sometimes jokes about creating a “Detect for America” program modeled on Teach for America that would funnel young graduates of elite colleges into cities in need of more investigators. I don’t think it’s a totally crazy idea. But taking the military analogy more literally, you could imagine creating a new federally sponsored higher education institution, modeled on the military service academies, to train detectives. You’d get a four-year college degree with different majors available, but with plenty of classes focusing on forensic science, law, and public safety research in sociology, economics, and political science. The institution could serve as a hub for ongoing research on subjects relevant to criminal justice but also train students to serve as apprentice detectives in big police departments or state police agencies.