proactive policing

Are Minneapolis Crime Increases Evidence of a "Ferguson Effect"?

Recent data from Minneapolis show an increase in shooting crimes but not other crimes, the same pattern as in Chicago in 2016. The likely reason is a reduction in police street stops, just as in Chicago in 2016.


Following the police killing of George Floyd and subsequent civil unrest in Minneapolis, some crimes–specifically gun crimes–have increased in that city while other kinds of crimes have not.  A"Ferguson effect" appears to explain this pattern. Minneapolis police have stopped making as many street stops as they made previously.  And given the unique responsiveness of gun crimes to policing activity, the tragic result of that pullback has been an increase in shootings.

This morning, Charles Fain Lehman of the Washington Free Beacon examined recent crime trends in Minneapolis in this very informative article–"Are Minneapolis's Police Protests Causing a Crime Wave? The specter of the 'Ferguson effect' rears its head amid Floyd protests." As explained in the article, an average of over 50 gunshots per day have plagued Minneapolis since Floyd's killing, prompting fears that hostility to the police is driving a violent crime wave.

As Lehman notes, police data from Minneapolis show firearm discharges at double 2019 levels.  Here is the data—with shots fired during the first half of 2020 being identified by the red line in the chart below:

Lehman's chart depicts data from the city's ShotSpotter gunshot detection systems. While gun crimes invariably increase during summer months, this chart shows an increase that is far different than normal seasonal variation–a substantial increase that immediately follows the George Floyd protests.

But, as Lehman explains, the data from Minneapolis do not show a general increase across all crime categories. Instead, the data show that most index crimes in Minneapolis are simply moving along with pre-existing trends. Lehman notes that "only rates of assault–particularly, second-degree assault, meaning assault with a dangerous weapon–have consistently risen since Floyd's death."  Lehman depicts all eight index crimes (arson, assault, auto theft, burglary, larceny, murder, rape, and robbery) and the only crime category with a consistent, post-Floyd-protest increase is assault–although homicides are generally up and robberies are trending upward as well.

Lehman further explains that the increase in shots fired and assaults could support an argument for a "Ferguson effect" in Minneapolis. The "Ferguson effect" was a term first coined by St. Louis Police Chief Sam Dotson III in late 2014, to account for an increased murder rate in some U.S. cities following unrest due to the police killing of Michael Brown in Ferguson, Missouri. Heather MacDonald (a law school classmate of mine) further popularized the term in a Wall Street Journal op-ed in May 2015.

MacDonald has recently suggested that a "Ferguson Effect 2.0" or "the Minneapolis Effect" is now responsible for recent violent crime increases, in Minneapolis and other large cities across the country.  But, as Lehman notes, in Minneapolis, while the "spike in gun violence definitely supports a renewed Ferguson effect, … the ambiguity suggested by many crimes going unaffected means the case is not conclusive." Lehman then discusses other research on crime increases following the Ferguson unrest that reaches differing conclusion on whether a Ferguson effect was responsible.

The point that struck me about the recent Minneapolis data is the pattern of crime increases, specifically increases that are concentrated in shootings and assaults, as well as possibly homicides and armed robberies.  A similar pattern of crime increases was present during the 2016 Chicago homicide spike.  A detailed paper on the Chicago spike by my University of Utah colleague Richard Fowles and me explains that in Chicago in 2016 there was a dramatic increase in gun-related crimes, but not other crimes. (See pp. 1600-01 of the study). Specifically, in Chicago in 2016 homicides increased substantially, by 58% year-over-year from 2015 to 2016.  There were also large (more than 20%) increases in robbery and aggravated assault–but not such large increases in other index crimes. Focusing specifically on gun crimes, there was a substantial increase in shootings in Chicago in 2016. Fatal shootings increased by 66% and non-fatal shootings increased by 44%.  (See Table 5).

The 2016 Chicago pattern looks eerily similar to the pattern that now seems to be developing in Minneapolis.  Just as Chicago shootings increased dramatically in 2016, so too in Minneapolis shootings are up significantly.  And just as Chicago's assault and homicide rates increased significantly in 2016, so too (apparently) in Minneapolis. There were 48 homicides in Minneapolis in all of 2019. A little more than halfway through 2020, there have already been 31 homicides in the city.

Professor Fowles and I explain at length in our paper the reasons for concluding that the 2016 Chicago homicide spike was caused by an "ACLU effect." Specifically, we discuss an agreement that the Chicago Police Department struck in August 2015 with the ACLU regarding street stops (often referred to as "stop and frisks"). That agreement was implemented in December 2015, and produced about an 80% reduction in the street stops that Chicago police officers conducted during 2016.  Our argument is simple: As a result of the ACLU agreement, police significantly reduced the number of street stops they made, leading to more illegal guns on the streets of Chicago, leading to more shootings and homicides. Our paper estimates that the reduction in street stops in Chicago led to about 245 additional victims killed and about 1,108 additional shootings during 2016.

The current pattern in Minneapolis may similarly reflect a reduction in police activity focused on preventing gun violence. As has been widely discussed in the media, the Minneapolis Council is moving to "defund" its police department–or, more precisely, to remake the police department into a "public safety department" with less focus on licensed police officers.  Amid such discussions, officials in Minneapolis have noted (according to an article by the Star-Tribune) a "reluctance of some Minneapolis officers to take initiative amid intense scrutiny."

This reluctance to "take initiative" could mean a reduction in street stops and other self-initiated police activity that might produce an increase in gun crimes.  A recent paper by Tanaya Devi and Rolad G. Fryer, Jr., for example, links declines in self-initiated police activities with increases in homicide rates (although the paper believes that federal "pattern-and-practice" investigations are an important causal factor, a point that I disagree with for reasons beyond the scope of this blog post). And, in Minneapolis specifically, there have been recent suggestions from police union leaders that Minneapolis police officers "are not going to put themselves out there to get the proactive stops to get the guns off the street … [b]ecause they don't feel supported, after the fact," as Sgt. Anna Hedberg of the Minneapolis Police Federation recently put it.

So what do the data show regarding police stops in Minneapolis recently? Lehman has shared with me data that he has pulled from the Minneapolis Police Department data dashboard.  The data reveal that police stops have declined significantly in Minneapolis since the Floyd protests began.  The following chart depicts the data for suspicious person stops, suspicious vehicle stops, and traffic enforcement stops.  The red line depicts stops before 2020; the green line depicts stops for the first half of this year.  As is clear from the chart, with the exception of a singular spike a couple of days after the protests began, police stops of all types are below those conducted in earlier years, particularly "suspicious person" stops:


And, similarly, data on police stops in which a person or vehicle was searched show a persistently lower level of police activity since the Floyd protests began.  The chart below depicts police stops in which a person or vehicle was searched, with the red line depicting pre-2020 police activity and the green line depicting activity from the first half of this year.

The fact that the timing of the increase in shootings revealed in the ShotSpotter data coincides so exactly with the decline in various stops and stop-leading-to-searches provides a reason for concluding that the reduction in police activity is a triggering mechanism for the increase in shooting crimes in Minneapolis.

Of course, other factors apart from a decline in policing activity may be at play in Minneapolis's crime increases.  Further analysis is required to reach definitive conclusions. For example, some might argue that reduced trust in law enforcement following Floyd's killing is responsible. And Minneapolis has been under COVID-19 restrictions for several months, a confounding variable in any analysis of crime trends.  But such general factors would seem to be candidates for explaining increasing or decreasing crime rates across-the-board–not just the unique increase in shooting crimes that Minneapolis is suffering.

Gun crimes are specifically (and quickly) responsive to law enforcement initiatives, a point that Professor Fowles and I explore in our earlier paper (pp. 1605-08). Sadly, hundreds of additional shootings and deaths occurred in Chicago in 2016 (concentrated in the city's African-American community) as police were redeployed away from street stops that helped to deter shootings. As policing activities that prevent gun violence are now declining in Minneapolis, crime victims in the city may suffer the same tragic consequences.

NEXT: FIRE Letter About the UCLA Letter from Birmingham Jail Controversy

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  1. Perhaps those inclined to use firearms were emboldened by the community outrage or angered by the police action.

    1. Drawing conclusions from small samples of noisy data is unjustified. Makes any conclusion meaningless.

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  2. I must be missing something subtle. This sounds suspiciously like saying “stop and frisk” was effective and should be expanded.

    It also sounds like saying that people routinely carry guns in the hope that if they don’t see a cop every few minutes, the coast is clear, and they can pop off a few rounds just for fun.

    1. I think he comes out and says exactly that in his paragraph about the ACLU effect.

      1. As well he should, as “stop and frisk” was effective and should be expanded.

        NYC and Chicago are not Mayberry, they can’t be policed with a hands off [figurative and literal] policy.

        1. Expanded to white people?

          1. If they live in high crime areas of the city, sure.

            1. Why do conservatives endorse “stop and frisk” (after clamoring for Obama’s birth certificate) while striving to enable Trump to avoid complying with subpoenas?

              Other than the right-wing racism, I mean.

              1. Because stop and frisk appeared to lower the number of violent shootings and murders in an area. And conservatives actually care about people dying of murder, especially poor African Americans.

                While liberals seem happy to say one thing, but adopt policies that lead to more death.

            2. Why just high crime areas? Every potential murder ought to be prevented, no?

              1. It’s about resources. There just aren’t enough cops to stop and Frisk everyone. So you concentrate on the high crime areas.

                Of course, we could just hire a lot more cops….

                1. And the cool thing is, once you concentrate the enforcement, the high crime areas turn up right where you concentrated. That’s how you know the policy makes sense.

                  1. That argument works for, say, burned out taillights. But burglaries, murders, and so on don’t happen in a given place just because the police spend time there.

          2. It already had been “expanded” to white people. And had been since 2003 in New York. (The program started in 2002, there was no race data for that year.)

          3. No. The founders intended the 2nd Amendment for whites only. Repeal the 14th and return to the Founders’ vision.

        2. As well he should, as “stop and frisk” was effective and should be expanded.

          Except NY’s stop and frisk was abolished years ago and we saw no negative effect as a result.

    2. just because something is effective doesn’t mean that it is either morally justified or constitutionally permissible.

  3. Didn’t New York reduce police stops, which the police exacerbated by practicing a “slow down” and crime went down.

    I feel like the data shows that police are irrelevant to preventing crime and that other factors control the rise and decrease in crime.

    1. Did crime go down, or did reported crime crime go down? If you know the cops aren’t answering are you really going to bother to report a robbery?

      1. but lets compare apples to apples, shootings were down. The broad idea is that police action is largely irrelevant to stopping crime. Which isn’t to say that they don’t stop some crimes, just that the preventative stops probably don’t.

        1. Ok, then, why is violent crime going up fairly quickly in NYC?

          1. Who knows?

            This is a not much data over a short period of time. It is not the sort of things causal relationships are based on.

            Lets talk in a couple of years.

  4. I don’t think anyone is surprised that crime is more effectively controlled when civil rights are ignored. We still shouldn’t ignore civil rights.

    Crime has been falling since 1993 and is at a low level relative to other times. The need for maximum enforcement that compromises rights is low.

    1. Crime is only low compared to the insanely high rates of the 70s and 80s. Crime is still higher than in the 50s, and many people speculate that crime in Victorian England was almost nonexistant being that there was an extreme panic over 5 murders of prostitutes. Something that wouldn’t even make the newspaper in most American major cities today.

      1. They had standards of behavior in Victorian England. This is modern America

      2. Crime is still higher than in the 50s,


        Something that wouldn’t even make the newspaper in most American major cities today.

        Are you on drugs? (If not, perhaps you should start.)

        1. Multiple murders at the same time are routine, even outside the favored targets of the media. Gangmembers routine shoot bystanders to get one victim. That is not usually widely reported unless the victims are white.

          1. Multiple murders at the same time are of course not routine, and do in fact make the newspapers. (Also, JtR did not kill multiple people at the same time; he was a serial killer.)

        2. Your assertion that the murder rate in the 1950s of ~4.5/100k represents higher crime than a murder rate of ~4.5/100k after 70 years of medical innovation, particularly in this area. If 1950s people had our medicine their murder rate would easily have been half what it was.

  5. Forget the spike in crime. That is practically child’s play. Even more people will die from COVID-19 due to the lack of social distancing at the resulting protests. This shows the absolutely necessity of requiring that police use only reasonable force rather than excessive force while showing respect for the community.

    Derek Chauvin’s (and the inactions of the officers who sat and watched) will result in many more deaths than just George Floyd.

    We need to train police to intervene when they see another officer using excessive or unnecessary force. By doing so, they are not only protecting the suspect, but the other officer.

  6. The BLM movement never makes any traction because they lump in the obviously unjustified shootings of people like Philandro Castile with the obviously justified shootings of Michael Brown aka “the Gentle Giant.”

    1. Kill me now. Unless I’m hallucinating you just left a not floridly racist or otherwise despicable comment. If the drugs don’t wear off before I finish I’ll respond in kind.

      I’ve never seen an ideological public advocacy organization that didn’t undermine its credibility with tribal allegiances. BLM is no exception. But like most non-ideologues, I neither make the perfect the enemy of the good nor shy away from criticizing groups I support. So I’m perfectly comfortable saying Michael Brown was a terrible hill to die on, but BLM’s overall cause is a just and important one, so I support it.

      As for BLM “never mak[ing] any traction,” what planet do you live on?

      1. Almost every BLM martyr was a criminal on the lam from the police. You had those like Brown, who committed violent high level felonies in the presence of (and in his case against) a police officer, were finally being arrested after a long string of petty offenses, combined with significant underlying health issues, or did something as brain dead as standing up in a moving paddy wagon. Mike Brown chose to make it a question of whether he, or his victim, Officer Wilson, was the one who walked away from their confrontation.

        So, as a society, what should we do for petty offenses? Should the police just ignore them? The Giuliani era Broken Windows approach to policing would suggest that has long term adverse effects. If the police never arrest people who have accumulated, and not paid for, a number of citations for petty crimes, then there will be no penalty for committing petty offenses, and they will naturally increase. Several cities, led by NYC, are currently engaging in catch and release right now, and it doesn’t seem to be working very well.

        The real problem here is that most of these BLM martyrs are statistical noise. With millions of arrests across the country every year, a small number of people are going to accidentally die resisting being legitimately arrested, and some of those are going to be Black. It is, at best, a handful every year, and there doesn’t appear to be anything systemic about the racial makeup of the deaths, on a per crime or per criminal basis, but only on a per capita basis, and that is because of the much higher rate of crime commission by Blacks, than of other groups. There is your systemic problem.

        Keep this in mind:
        – if Floyd had not had a string of petty offenses that he had blown off, he would probably still be alive today
        – if he had not tried to escape police custody, he would probably be alive
        – if he had not taken roughly half the typical lethal dosage of fentanyl, he would probably still be alive (fentanyl severely impacts the Will to Breathe, based on excess CO2)
        – if he had not inherited Sickle Cell Disease, he would probably still be alive (likely his death was due to his heart stopping due to O2 starvation, due in great part to his red blood cells sickling).
        – if he hadn’t had COVID-19, he might still be alive today (he appears to have had some outer lung damage, that could be COVID-19 related).
        – if he had not had a history of heart arrhythmia, he might still be alive
        – if he had not been smoking pot (affecting judgement) he might be alive
        – if the police had let him escape, he might be alive
        – if the police had not put him in that neck hold, he might be alive today.

        1. Thanks for responding, Bruce, but that’s more question begging, straw manning and victim blaming than I have the energy for today.

      2. What traction have they made? They’ve gotten some virtue signaling support from white liberals, but I haven’t seen much evidence that there will be any real reform.

        1. Obviously legislation awaits a sympathetic Congress (both chambers) and Executive. The majority and growing support for BLM should go a long way toward making that happen.

  7. I have no doubt you will find somewhere experts willing to assert that ShotSpotter technology reliably distinguishes gunshots from other explosive noises, particularly fireworks. Does anyone know whether that specificity is good enough to permit Cassell—without making a fool of himself—to equate increased ShotSpotter reports with increased gun crime?

    I’m looking for someone with an actual acoustical engineering credential, who could discuss complications. Google searches for descriptions from ShotSpotter system boosters turn up weak sauce, long on speculation and defensive-sounding generalities, short on specifics. Lots of talk about how the “real value” of the system is in helping police choose where to police. That doesn’t sound like a confident endorsement that the system works to detect specific gun shots, or can actually distinguish them from other noises.

  8. The only statistic not dependent on a police report is the gunshots. I know from experience – In Baltimore after Freddie Gray it was next to impossible to get the police to file a breaking and entering (Burglary/Larceny) report. They wouldn’t even show up unless there was a physical injury. This may drive some of the statistics in Minneapolis.

    1. “This may drive some of the statistics in Minneapolis.”

      Probably. There is a reason Disraeli called out stats as a third distinct form of lying.

      Cops don’t respond and/or they suddenly start spending an extra hour at each place where they do respond.

  9. Doesn’t matter what “effect” it is. We pay cops to prevent crime without strangling people and randomly tossing innocents up against the wall.

    If they can’t do that, fire them and replace them with people who can.

    Same with the prosecutors who are blaming increased crime on bail elimination. The prosecutors are supposed to keep criminals off the streets by trying and convicting them, not holding them in pre-trial detention without bail.

    If they can’t do that, fire them and replace them with people who can.

    1. I bet you respond to incentives. The incentive for police now is to keep their heads down and do as little as possible. Perfectly rational.

      “Fire” cops en masse and you won’t get replacements easily either.

      1. Lawyers get attacked all the time. Journalists get attacked all the time. Politicians get attacked. Teachers. CEOs. Government workers.

        All of them manage to continue to do their jobs.

        Bespeaks an entitlement of this one group that isn’t so professional.

      2. ” The incentive for police now is to keep their heads down and do as little as possible. Perfectly rational.”

        Of course. That’s why you have to fire the ones who keep their heads down in addition to firing the ones who use unjustified force.

  10. “But, as Lehman explains, the data from Minneapolis do not show a general increase across all crime categories. Instead, the data show that most index crimes in Minneapolis are simply moving along with pre-existing trends.”

    I take issue with this. The shotspotter system (in theory) registers all gun shots. Other crime data rely on 911 calls. It is possible that other crimes are up but not being reported.

    Some victims may be cowed into silence. Some victims may now hate the police and refuse to call.

  11. The trouble with stop-and-frisk, aside from it being a Fourth as well as Second amendment violation, is that it leaves the population suddenly vulnerable whenever the police decide they have better things to do today than stop-and-frisk people in poor neighborhoods. I believe red-state experience clearly shows that simply legalizing concealed carry does a better job of protecting the innocent, especially from orchestrated riots such as the present ones.

  12. So many “mights” and “mays” in these comments, with 0 data to support them. The claims made here are supported by data. The counter claims, especially those that question the data, are supported by: supposition. As with any statistical analysis, outliers prove little/nothing. Anecdotes about this one dude, or that guy over there are superfluous at best.

    Specific effort was made here to study whether other, non-observed factors were at work: via looking at incidences of other crime. They weren’t. I notice nobody questions that part. But, because this study lacks a footnote with affirmative attestation by an acoustical engineer; that alone refutes ALL of it? Nonsense. Refutation, like a claim, only goes as far as its evidence. Is there any evidence that said engineer would disprove of this study? No? Until there is, their absence is evidence of: nothing.

    We(every relevant manager in the USA) use the type of analysis above, all day, every day, to make decisions. Why? Because it get results. Does it miss? Yes, but rarely. We don’t allow noise to deter us. Introducing COVID into this analysis == noise.

    This is Isn’t reason a requirement here? It is not reason to take what appears to be a proper statistical analysis and try to counter it with tired quotes about statistics and lying. Leftists wonder why they lose. Answer: their own intellectual laziness. It is the single biggest factor. It is easier, so it must be better, right leftists? Example: “I’m with her!”, when only a modest intellectual effort would have shown you the country wanted a POTUS that was “for them”. Yeah, the Russians tricked you into your laziness. That same laziness is on full display in these comments.

    Example: we are always being told by the left that we have to listen to the science + data, even when there isn’t any, without caveat, without methodology questions. Even when the methodology is screaming out to be questioned, no, we must accept all as is.

    But here, as soon as the data + science don’t go the way they like? Out come the caveats and the methodology questions and even worse: the platitudinous responses.

    Hey leftists: let’s see you put 1/4 the effort you have here, everywhere else you demand we listen to the “science + data”. Oh, no, can’t do that, can you? That would require: aversion to hypocrisy, attention to detail, intellectual rigor, and of course…

    1. Formulaic – as if AI wrote your comment.

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  14. “just as in Chicago”

    Note to resident racists:

    Chicago doesn’t even make the top 10 when it comes to murders per capita.

    But good to know that you racists are still harping on about Chicago because that’s where Obama lived.

  15. P.S. Meet the Republicans representing cities with a higher murder rate than Chicago:

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  18. Using’s logic, the crime increase is due to the control Republicans have over our schools, media, and inner cities, not to mention conservative messages poured out by Hollywood.

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