MS. INDIRA LAKSHMANANThanks for joining us. I'm Indira Lakshmanan sitting in for Diane Rehm. She's on a book tour. For more than 20 years, violent crime in the United States has been falling dramatically. But preliminary FBI data released last month for the first half of last year reveal an unexpected uptick, especially in murder, with sharp increases in cities, including Washington, D.C., Baltimore, St. Louis and Milwaukee.

MS. INDIRA LAKSHMANANJoining me in our Washington, D.C. studio to talk about violent crime in this country, factors that drive it and what can be done to stop it, Paul Butler, a professor of criminal law at Georgetown Law School. From a studio at WRLN in Miami, Barry Latzer, author of the new book, "The Rise and Fall of Violent Crime in America." And from an NPR studio in New York, Khalil Muhammad of the Schomburg Center for Research in Black Culture.

MS. INDIRA LAKSHMANANWe'll be taking your questions and your comments all throughout the hour. If you want to reach us, you can call 1-800-433-8850. You can send us an email to drshow@wamu.org or join us on Facebook or send us a tweet. Welcome, gentlemen.

MR. PAUL BUTLERIt's great to be here.

MR. KHALIL MUHAMMADThank you for having me.

LAKSHMANANThanks. So Barry, let's start with the underlying trend over the last 20 years that I think is really going to surprise many listeners who watch local news and catch those high profile crimes that grab the headline and that is the story of the dramatic decline in violent crime in America since the mid '90s. Tell us when violent crime peaked in this country and how dramatically it's dropped and why.

MR. BARRY LATZERDelighted to be with you, Indira.

LAKSHMANANThank you.

LATZERViolent crimes rose from 1960 to 1990 at a rate of 353 percent. So this is probably the biggest rise over sustained period in violent crime in the history of the United States. A big factor in this were the demographics. You had this baby boom generation reaching their most criminogenic years in the last '60s. That's the ages 18 to 25. Once this generation began to age out of crime, which occurred in the early 1980s, crime began to fall.

LATZERThere were, of course, other factors involved, but we can perhaps address those in a minute or two. So crime began to fall in the early '80s and it probably would've continued to fall were it not for the fact that the next generation, the boomerang, the next cohort, excuse me, after the boomers, took up crack cocaine. And crack cocaine became a scourge that really sent crime souring all over again and this happened the late '80s and early '90s.

LATZERThe criminal justice system had toughened up. The crack cocaine scourge itself was so devastating to this next generation that after a while, and it didn't take too long, maybe six years or so, the youngsters who took up this crack cocaine began to realize it was so self destructive that they needed to abandon it. Well, that happened in around 1993, 1994 and that's when the big crime trough, the big drop in violent crime began.

LATZERAnd it continued really and we probably are still continuing it now. We don't have enough of a trend to determine whether crime is really going up again or not. But it appears to be continuing. A one-year spike is not enough to draw any real conclusions.

LAKSHMANANAll right. Well, Barry, what, in your view, because you've really studied the crime data from the end of World War II into the 21st century, what, in your view, is the single biggest reason for the decline that we've seen?

LATZERWell, the demographic change was a major reason. And as I explained, that had to do with the baby boom generation aging out and their children getting out of the cocaine business. So that's certainly factor one. Factor two was the hardening, the toughening of the criminal justice system. The system had caved when crime rose suddenly and massively in the last 1960s. And then, there was tremendous public pressure to strengthen the system with the more serious penalties, greater number of police officers, more arrests and sending more people to prison for longer periods of time.

LATZERSo the hardening or toughening of the criminal justice system combined with the demographic changes, drove down crime in roughly the mid 1990s.

LAKSHMANANBut I was struck in your book that you really single out one other thing beyond demographic changes, aggressive policing and sentencing. You single out the rejection of drugs and specifically crack cocaine and criminality by the generation who sort of aged into that so-called crime, you know, committing population in the mid '90s because they saw the toll that it took on their parents generation and on their neighborhoods.

LATZERWell, the toll it took on themselves and their friends because you -- first of all, you had all of the health problems associated with cocaine, which is a very devastating drug. Aside from the addictions, you have physical ailments associated with the cocaine addiction. Second of all, the criminal justice system had cracked down and more people were subject to arrests than imprisonment.

LATZERThird of all, was the crime associated with it. The distribution of cocaine was conducted by gangs, largely in minority neighborhoods, and these gangs, of course, having no authority they could turn to when they competed with one another began to engage in gun violence. And, of course, this lead to a great increase in assaults and in murders. So we call these behaviors, when you copy on another, contagions. And contagions can either be positive or negative.

LATZERThe beginning of the crack era involved a very negative cocaine where cocaine use became -- I'm sorry, or negative contagion where cocaine use became a negative youth contagion. Well, the end of cocaine, I think, was a positive contagion. It was as if youth became aware of the devastating impact of the drug and then they -- it became uncool. We have a fascinating studies of communities where the youth simply abandoned cocaine and this is what helped drive down crime.

LAKSHMANANAll right. Paul Butler, you study criminal law. How much, if at all in your view, did stepped up law enforcement and incarceration since the 1980s and '90s have to do with this drop in crime?

BUTLERIndira, when we talk about crime and violence, the first thing I want to know is why it's likely that no one is going to go to jail for poisoning the water in Flint, Michigan. And then, I want to know why nobody went to jail for a housing crisis in which folks gambled on mortgages that were owned by poor people, many poor people of color, that caused this devastating loss of wealth in the African American community.

BUTLERIf we're gonna talk about culture, what kind of culture allows for the gross wealth equality -- inequality that we see in this country? So, again, I'm thinking about the golden rule, the people with the gold make the rules so it's this top 1 percent that's making this criminal law that's resulting in millions of poor people being locked up. And then, we can have a conversation about what makes crime go up and go down at times.

BUTLERAnd the answer is, we don't know. All we have is a bunch of correlations, things that happen at the same time. Now, we can rule out some causes. Incarceration does not seem to have had much of an effect. How do we know that? Because in some cities, in some states, incarceration went up, the crime wave went up. In other cities like New York, for example, the incarceration rate went down and guess what, the crime rate went down as well.

BUTLERSo, you know, people come up with all kinds of explanations. The book "Freakonimics" famously attributed abortions, the availability of safe, legal abortions to women, as a cause of crime going down. I think lead paint, making that illegal, had a lot to do with it because we know that when people are exposed to lead, that makes them at risk for violence, which is another reason I'm so fed up with what's going on in Flint.

BUTLERSo demographics, maybe. You know, as a scholar, I want to be careful not to over claim. I want to admit what I don't know. And no scholar can purport to know why crime goes up or down. I wish we did because then, we could just stop it.

LAKSHMANANAll right. Well, Khalil Muhammad, in the brief time we have before we go to a break, do what extent, in your view, does economic disadvantage correlate with violent crime rates or is it causal even?

MUHAMMADI'm going to take the tack that Paul took, which is that we don't have clear lines of explanatory force. We simply don't know. What we do know is that communities that have greater economic mobility and access to the fruits of their own labor tend to have more means at their disposal to settle differences. And the most obvious example would be that wealthy people tend to rely on civil courts to settle their disputes rather than physical violence to regulate behavior that they perceive as harmful or a threat.

LAKSHMANANAnd so when we see rates of higher education and better economic conditions in those community, violent crime rates also go down?

MUHAMMADWell, what we see is that we don't have purported street violence. What we have is domestic partner violence in all kinds of communities. We have high rates of suicide in communities. So we have to also talk about different kinds of violence. And crime and violence are not one and the same. Crime tends to be much more elastic, much more socially constructed and based on policing practices, rather than violence which leaves generally a dead body in the street or someone experiencing severe harm.

MUHAMMADSo moving from middle class to elite communities into poor communities, you have a difference -- expression of violence.

LAKSHMANANAll right. A lot more to talk about. We're gonna take a short break. I look forward to hearing your comments and your questions. Stay with us.

LAKSHMANANWelcome back. I'm Indira Lakshmanan sitting in for Diane Rehm. This hour we're talking about violent crime in America, what caused its dramatic drop in the last 20 years and whether we're seeing a turnaround in that based on preliminary data for the first six months of last year.

LAKSHMANANJoining me to discuss the topic: Paul Butler, a professor of criminal law and civil rights law at Georgetown University Law School. From WLRN in Miami, Barry Latzer, emeritus professor of criminal justice at John Jay College of Criminal Justice at City University of New York and author of the recent book, "The Rise and Fall of Violent Crime in America." And from NPR studio in New York, Khalil Muhammad, director of the Schomburg Center for Research in Black Culture at New York Public Library.

LAKSHMANANSo, Barry, I want to come back to you. Because in your thick book, full of graphs and charts and a lot of data, you also emphasize what you describe as a culture of violence among certain ethnic groups in America being more important than socioeconomic adversity. What do you mean by this? And how can we understand your analysis without it seeming to be tinged with prejudice?

LATZERLet me pick up with remarks by Khalil in answering you. I think he's absolutely right that more affluent people, middle-class people and wealthier people resort to courts and law and lawyers when they have interpersonal conflicts. Whereas poor people tend to resort to violence much more. Now what we see, however, is that among groups that are poor, some groups resort to interpersonal violence much more than others. And this is an issue that criminologists have not really grappled with. And, of course, this is where you have concerns about impugning certain people or certain groups.

LATZERThe facts are that in the South of the United States, for well over a century, both Southern whites and Southern blacks had very high rates of interpersonal violence. That is, when they had conflicts within their families, among themselves and their friends, with other acquaintances, there was a tendency to use violence to resolve those conflicts. And this led to very high rates of assault and of murder in the South. And this was noticeable from the 19th century on. And as I say, it was a cultural manifestation associated with both whites and blacks.

LATZERWhen African Americans migrated to the northern cities, which occurred throughout the 20th century, but especially, initially at war time -- World War I and World War II, when there were more economic opportunities -- and then in the '60s and the '70s. In the '60s you had the migration of 800,000 African Americans to cities of the North and the West Coast and, in the 1970s, another 1.5 million. Well some of this interpersonal violence that took place in the South was effectively transported to the North.

LATZERSo African Americans had high rates of interpersonal violence in Northern cities and also engaged in other violent crimes -- robbery, for instance -- because there were great opportunities due to the greater amounts of wealth and the great mobility of people in the Northern cities, there were great opportunities for robbery in the North. So we had a high involvement of African Americans in the big crime tsunami from the '60s to the '90s. And this was a contributing factor to the rise in crime.

LATZERI just want to make one more comment, if I may, to Professor Butler's remark about lack of proof that incarceration impacted the crime rates. A study by Steven Levitt, the economist, found that the increase in incarceration in the 1990s reduced violent crime by 12 percent and reduced homicide by 12 percent. And in another study -- well known I think, because it was published in a book on criminology -- William Spelman found that imprisonment contributed to 27 percent of the violent-crime decline. And that was just up to 1997.

LATZERSo these studies have all shown that -- at least the studies that I know of have all shown that incarceration did definitely reduce violent crime rates.

LAKSHMANANAll right. Well, a lot of issues there in what you've said. One, about sort of Southern violent culture, what you're referring to as Southern violent culture being imported up into the North with the great migration in the 1960s. Also this issue about incarceration. Let's unpack them one at a time. I'm struck also by, in your own writing, though, Barry, you've written about the contradictions between indictments, convictions, imprisonment in New York being in decline, while crime was itself declining in New York.

LAKSHMANANSo, Paul Butler, pick up that question that he says about the -- about a link between incarceration versus a drop in crime rates that he's asserting. And also the question of, is it taking known criminals off the street versus is it having a deterrent effect on future potential criminals?

BUTLERFirst, I have to express my incredulity at talking about Southern violence without talking about the history of white supremacy in the South and the way that exploitation of African Americans was enforced with lynchings and hangings and shootings and extraordinary economic coercion, so that, after emancipation, we were still little better off than slaves. So I don't know if it makes sense to think about violence without that much larger, structural violence.

BUTLERBut if we want to think about this relationship between whether putting people in a cage for years and years makes their crime rate go down, even the best studies that Barry cited says that 75 percent of the reason that crime went down we don't know. Again, his best study says that there's like a 25 percent connection between reducing crime and the rate of incarceration.

BUTLERBut one thing we know is that with 2.5 million people locked up now, the current rate of incarceration is actually criminogenic, which means that it causes people to commit more crime. When you're locking up that many people, you're locking up a lot of young, nonviolent offenders. And sending them to prison is like sending them to finishing school for crime. They learn how to be better criminals. And when they come out, they haven't received the kinds of services that they need to be contributing members of society.

BUTLERSo, again, we have to be really careful when we think about relationship between incarceration and crime. What we know, just real quickly, is that desperate poverty, with ready access to guns, is the best predictor of who's at risk for violence. And you just cannot compare the level of poverty that African Americans experience with any other group in this country.

LAKSHMANANAll right. Well, Khalil, I mean Paul has alluded to this country's history of institutionalized cruelty and discrimination against African Americans from slavery to segregation. Tell us how you see this factoring into the crime figures that we're talking about, above and beyond the economic question.

MUHAMMADWell, it's really important to get this history right. Barry does point out a very long-standing view among historians of violence, that cultures of honor in the South and in the nation -- you know, we lost Alexander Hamilton to a duel -- by the very nature that even men of tremendous honor and prestige resorted to violence to settle differences. So there is a there there, when it comes to the culture of honor and violence in this nation. And the South was the hot bed for that.

MUHAMMADBut the casual relationship of the migration of blacks to the North, as in kind of uninterrupted train of a kind of viral infection of violence that moves into these cities is deeply problematic. And it's problematic for this reason: One, it removes any notion of structural violence and inequality that exists in the North. So it's as if black people come to the promised land and they have opportunity, but the opportunity is really for robbery and not to actually fight against the kinds of what we used to call de-facto racism in the North.

MUHAMMADToday we know much more, that there was systematic discrimination at every level of society in our economic sphere as well as in the criminal justice system. We know that white police officers in the 1900s, of Irish ancestry or Polish ancestry or German ancestry, were much more likely to abuse and to target African Americans on the streets of urban America as they were their own kin men and especially those who were better off in those communities. So there is an active pressure working against African Americans that is both societal and within the criminal justice system that moves across time both in the South and in the North. So we don't just get an explosion of violence because black people show up.

MUHAMMADThe other thing is, we also know that immigrant communities -- and there are other criminologists who've studied this -- experience tremendously high rates of interpersonal violence, partly because they were poor, partly because they were victims of nativism, a xenophobia, in Chicago, Philadelphia, New York, between the 1900s and the 1930s. The difference between blacks and immigrants in those communities was a difference in degree, not in kind.

MUHAMMADAnd the opportunities for moving out of those communities of high rates of violence had everything to do with economic opportunity as well as new messages of inclusion, of incorporation, of saying you may have been born in Poland, you may have been born in Russia, but you are now an American, you're part of us. Those narratives of inclusion awaited African Americans well into the 1970s, '80s, even to this day.

MUHAMMADAnd I'll say one last thing. I participated on a panel of the National Academy of Sciences two years ago. A report was issued on the causes and consequences of high rates of incarceration. That panel of scientific experts from around the country found that, at best, prison had an incredibly small or very modest impact on deterring violence in this country. So the 25 percent high-water number has been essentially rejected by the nation's leading scientists and, at best, falls somewhere closer to single digits.

MUHAMMADI think that's important because it's not one or two studies. It was a review of all known data and studies as late as 2014.

LAKSHMANANHmm. Summarized by the National Academy of Sciences.

MUHAMMADCorrect.

LAKSHMANANAll right. Paul Butler, even with the dramatic fall in violent crime that we've seen since the mid-1990s, African Americans were then and remain now disproportionately reflected in crime statistics, both as victims and as perpetrators. Why?

BUTLERSo, just to add one more point to the relationship between incarceration and crime. Crime has gone down just -- not only in the United States but all over the world, and especially the Western world. And none of our Western allies use incarceration at nearly the rate that we do. And yet they've experienced the same dramatic reductions in crime. African Americans are at risk for certain kinds of violence because of poverty, because of the kinds of structural deprivations that we experience as a result of 400 years of entrenched white supremacy.

BUTLERSo black people don't commit crime because they're black. They commit crimes -- some kinds of crimes, again, because they don't have access to the kinds of goods, the kinds of services from the government. You can go back to the New Deal, when African Americans were effectively barred from Social Security, from the GI Bill, to the present day when, again, it seems like the main time that the police are interested in us, and especially young men and women, is when they mess up. Otherwise they don't get the same kinds of services that we know -- we know how to reduce the risk of people committing violent crime, but we're simply not willing to invest those resources in young black men and women.

LAKSHMANANI'm Indira Lakshmanan and you're listening to "The Diane Rehm Show." Khalil, Paul just brought up this, you know, the mention of the New Deal and the GI Bill and how they helped reduce crime. We know that more education and middle-class status decreases groups' involvement in violent crime. But it seems that the New Deal and the GI Bill did not help all groups, across the board, equally.

MUHAMMADDid not, because everyone wasn't benefiting from the economic access that the New Deal afforded them. So African Americans lost their jobs in -- disproportionately in the context of the Great Depression. And when the New Deal programs, from the WPA to the Agricultural Adjustment Act and so many other programs, meant to help to adjust the economic dislocation of working-class Americans, meant that African Americans were also not hired for those jobs.

MUHAMMADSo the New Deal was part of a cultural rewiring of this nation. I think the really interesting thing about the New Deal is that it comes on the heels of the Prohibition Era. It comes on the heels of the Volstead Act, which criminalized the manufacture and distribution of alcohol, which created huge underground economies for bootleg liquor. Who were the players and the agents of that underground economy? They were young, white, often second-generation immigrant men of European ancestry. They resorted to gun violence and to gang violence to settle their differences over the fruits of the illegal market in alcohol.

MUHAMMADHow did the nation respond? It completely reversed course. It went from a moment for the tremendous capacity for mass incarceration by building as many prisons as the nation could afford in order to incarcerate all those white ethnic men, and instead -- under Franklin Delano Roosevelt, first as governor of New York and then later as president -- rolled back the carceral capacity in that moment to incarcerate essentially an entire generation of young white men.

MUHAMMADIt wasn't just a set of forces that compelled them. There was very much a cultural understanding that this was unfair to communities that were already disadvantaged by the Great Depression, already disadvantaged by nativism and xenophobia. And what kind of nation would we be if the only thing we could offer poor and dislocated young men was a long prison system for participating in an underground economy because that was their best economic outlet from their communities.

LAKSHMANANAh.

MUHAMMADSo the New Deal comes after that and fundamentally rewires the possibilities for young, ethnic white men and women to be fully incorporated into the economic system of America.

LAKSHMANANOkay. Barry, bring us back to the present day. The latest data from the FBI, out just last month, shows that in the first half of last year, violent crime overall rose 1.7 percent and murder, in particular, rose more than 6 percent. Tell us about the data and what it means. It's such a departure from the trends of 20 years.

LATZERI need to respond, Indira, to the previous comments first, if I may. First of all, during the Great Depression, starting in 1934, crime declined. And it declined for whites and for blacks. In fact, that was the start of the great crime trough. So for all of the massive economic dislocations of the Depression, we had a decline in crime and not an increase in crime. As a matter of fact, there's no consistent relationship between general economic conditions and violent crime in this country. When the Great Recession took place in 2007, 2008 -- which also, of course, caused great dislocations -- crime continued to decline. We remained in the crime trough.

LATZERSecond of all, insofar as African-American violent crime goes, you have to remember that almost all of this crime prior to the 1960s was black on black. Almost all of the homicides, almost all of the assaults were black on black. And whenever you had a black victim, well over 90 percent of the time, the perpetrator was black as well. So if we're going to analyze victimization here, I think we need to look at this from the standpoint of who is victimizing whom.

BUTLEROh, give me a break. Barry knows very well that that's the same rate for whites...

LATZERAs for the -- excuse me, excuse me...

BUTLER...90 percent -- 90 percent of white victims are...

LATZER...excuse me. I don't think he's...

LAKSHMANANOkay.

BUTLER...victimized by white people.

LAKSHMANANAll right. We're going to have to go to a short break now. When we come back, we're going to go to your calls and your questions and continue to debate this very much of a lightning-rod question. Stay tuned.

LAKSHMANANWelcome back. I'm Indira Lakshmanan, sitting in for Diane Rehm. This hour we're talking about the 20-year drop in violent crime in America and last year's figures that suggest a possible turnaround in that trend, an uptick. Joining me to discuss this, Khalil Muhammad, director of the Schomburg Center for Research in Black Culture at the New York Public Library, Paul Butler, professor of criminal law and civil rights law at Georgetown University Law School and Barry Latzer, emeritus professor of criminal justice at John Jay College of Criminal Justice and author of the new book "The Rise and Fall of Violent Crime in America."

LAKSHMANANBarry, I want to get back to what we didn't address before the break, which is this latest data from the FBI, preliminary figures showing that in the first half of 2015, violent crime actually showed an uptick. What do you make of these figures? Does it represent a change in this positive, long-term downward trend that we've been talking about?

LATZERI looked at violent crime in the 10 biggest cities in the United States, homicide in particular, from 2010 to 2015, and I looked at all the data for 2015. The FBI only has the first half of the year. I did not find any increase. The total homicides for the top 10 cities were about 2,229 in 2010, and in 2015, they were 1,878. So there's no trend upward in violent crime. However, in some cities, obviously there is an uptick, and those cities could be a harbinger and may not be. We don't have enough data for a trend yet.

LAKSHMANANSo Barry, your point is that the FBI figures that were widely publicized last month in the press are actually somewhat misleading because they only looked at the first half of the year?

LATZEROh no, no, no, no, the figures are valid. What we don't know is whether this is the start of an upward trend or not. Now the figures are the same figures that I'm using, it's just that I had some additional information that I was able to put into it. Nothing wrong with the figures, it's just that one year is not enough to indicate a trend.

LAKSHMANANAll right, well there has been some talk in the news about the so-called Ferguson effect. FBI Director James Comey a few months ago said he had heard anecdotal information that police were being less proactive in cracking down on crime for fear of being caught on videotape engaging in conduct that might be criticized. The White House distanced itself from Comey's remarks. What do you say, Barry? Are police indeed holding back? Can we link that to anything that's going on in this last year?

LATZERI've seen no evidence of this at all. There was a study that just showed that crime rose -- was low before the Ferguson incident and then rose afterwards. That's not sufficient to prove that there's a Ferguson effect. There are going to have to be systematic studies to demonstrate that, A, the police are pulling back in some way, and that B, that this actually has an impact on crime.

LATZERI don't say it doesn't exist. What I say is there's no proof yet.

LAKSHMANANAll right. Let's go to the calls. We have Robert on the line from Miami, Florida. Robert, you're on the air, go ahead.

ROBERTYes, good morning. How are you doing?

LAKSHMANANThank you, good morning.

ROBERTI just want, you know, I'm a black man, and I live in Liberty City, Miami and we've had 36 children within the year have been killed, and the perpetrators are young black men waging war on each other as a result of this whole thing. And in Chicago, we just had 2,900 shooting victims and almost 500 homicides. I'm insulted by someone who suggests that because you live in poverty, or you live in a bad environment, that compels you to go pick up AK-47 and shoot people.

ROBERTNow at some point, I would like to the two professors to address this. Either we have, in our communities, we need to value each other's lives, or we don't. It just -- I'm talking to young black men that I mentor in the inner city. I talk to them about accountability, responsibility and choice, not to run towards the chaos.

LAKSHMANANOkay, Robert, thank you very much. So Paul Butler, take up Robert's point. He says that we're being dismissive of black-on-black violence, and we shouldn't be making excuses for it.

BUTLERWe're trying to think of better ways to keep families and communities safe. And we know that things like locking up every black man you can and throwing away the key just don't work. So what it's about is thinking about public health ways. Barry used an interesting word, contagion. Violence is like other kinds of diseases. It spreads, but it can be contained. Again, we know the kind of investment in communities that it takes to contain violence. We're just not willing to devote those resources to the African-American community.

LAKSHMANANAll right, let's go to another call from Simi in Fredericksburg, Virginia. Simi, you're on the air.

SIMIHi guys, big fan.

LAKSHMANANThank you.

SIMIKhalil and Paul actually made the comment for me. I just want to reiterate that whenever there is poverty, people are hungry, their blood sugar levels are low, they may resort to drugs like the current heroin epidemic we have, prescription drug epidemic we have in Virginia. This is an economic issue. People are economically depressed. When there is a recession in any place in the world, I'm thinking of World War II Germany, whenever there's a recession anywhere in the world, there's a depression for the minority group.

SIMIAnd you can do the correlation between what happened economically to the minority group in Germany and think about what's happening to America today.

LAKSHMANANAll right, Simi, thank you so much. Khalil, Simi is saying that economics plays a great role in violence. Can you respond to that?

MUHAMMADWell I think it's -- yeah, so here's the thing. We need to get away from correlations and causation in the strict sense that we do. What we know is in America, we can do better. We can do better in terms of our government policies, we can do better in terms of our cultural norms, we can do better in terms of the stories we tell about the world we live in.

MUHAMMADWhat we know is that we have intergenerational structurally racist poverty that exists in America all across America. And that structural racism makes it likely that people who are in communities where violence is more normative than not means everybody more's susceptible to it. So to extend the work of Gary Slutkin and those who work on Cure Violence, which is an interruption mechanism to reduce violence in communities, their basic point is that if you are in communities where you are ravaged by economic dislocation, where people are much more likely to spend their free time out on the street because they're not at work, there's going to be the greater likelihood of exposure to violence, which will then later produce violence by those individuals.

MUHAMMADSo that's a reality, and we can slice it and dice it a million different ways. What we know is that we've not done well by these communities, and those communities that we have neglected happen to be overwhelmingly poor, black and brown. In white America, it's not an accident that we have evidence that middle-class white Americans are now experiencing the kind of economic dislocation that black Americans have been experiencing for much of the 20th century.

MUHAMMADThis kind of cycle eventually catches up with everyone, and therefore what's happening in those communities, tremendous, tremendous drug addiction and related crime and violence in those communities, as well as suicide, which is a form of violence. So we have to expand our definition of crime and violence to be more inclusive of the relationships of economic misery or dislocation or insecurity that exists across America, rather than focusing on street, gun, stranger gun violence or what the caller, earlier caller, referred to on black-on-black violence, which is -- itself has a history as a way of saying black people are their own worst enemies.

MUHAMMADWell, black people can only be trapped in these narratives of racial pathology precisely because that's the only way we've ever talked about these issues.

LAKSHMANANAll right, Paul, I want to push this conversation back to the present day. Barry Latzer told us that the FBI statistics that we saw last year, the ones he has analyzed for all of last year, you know, they may show some slight uptick, but he doesn't think that it departs from the long-term trend we've seen of a decline in violent crime. I want to ask you, what are the steps that governments and law enforcement need to take to maintain this positive downward motion in violent crime over the last two decades? What are the things that are working?

BUTLERSo I actually agree with Barry that there's no reason to think that the overall downward trend is changing. So crime has been going down for about the last 20 years, but every now and then there's a year where there's an uptick. So we only have data for half of 2015, but even if it turns out that there is an uptick, again I think there's reason to be optimistic about the overall ways that we're keeping people safe.

BUTLERSo part of the Black Lives Matters movement is -- one of the tremendous contributions they're making is helping us understand that if we're only looking at crime, that's a fairly kind of narrow lens to understand the dynamic that prevents families from being whole and communities from being safe. So we can't talk about crime without talking about employment. If we're going to talk about race, the African-American unemployment rate has always been twice the white rate. You can't divorce that from a conversation about crime.

BUTLERSo again, it's not just crime, it's economic inequality. It's the lack of health services to the communities that most need it. And again, I just can't stop thinking about Flint, where the poor, African-American community had poison water, government officials knew this was going on, wouldn't drink the water themselves, but it was fine for those low-income African-Americans.

BUTLERSo, you know, white supremacy is the big, scary concept, but we cannot talk about ways to reduce people from being at risk from violence without thinking about white supremacy.

LAKSHMANANAll right, we have an email from David, who is referring to something that you referred to earlier in the show, Paul. In the book "Freakonomics," the author is noting a relationship, a correlation between the legalization of abortion and a drop in crime about 20 years later. And the listener wants to know, does this theory have any validity, and if this relationship is correct, what does the future look like vis-à-vis limitations that might be possible on abortion rights?

BUTLERYeah, so again it's one of those correlations that Khalil just mentioned that we have to be really careful about. It is true that after Roe v. Wade made safe legal abortions available for many more women, around the time that that happened, a few years later, when men, young men, reached their most crime-committing -- likely-to-commit-crime years, the crime rate went down. Now is that why? We have no idea. All we know is it's something that happened around the same time.

BUTLERAgain, I'm much more impressed with the evidence, that lead study, that lead point, getting that poison out of people's homes, and it was disproportionately in poor, black people's homes like Baltimore, getting that lead out. We know that makes people at risk for committing crime, at risk for violence. So I think that had a tremendous amount to do with it.

LATZERMay I comment, Indira?

LAKSHMANANYes, please. I just want to say I'm Indira Lakshmanan, and you're listening to the Diane Rehm Show. Go ahead, Barry.

LATZERI studied both issues and wrote about them in my book, the lead and the abortion issue. Both of the studies are flawed for this reason. The same cohort that was affected by the removal of lead from gasoline, the same cohort that had fewer births of unwanted children because of abortions, also was involved in the big cocaine usage and the crime spike associated with the cocaine usage. So if the same cohort is responsible for the crime spike, as well as the crime drop, it seems to me the argument that lead was responsible for the decline in crime or abortions were responsible for the decline in crime are flawed because the same group is committing a lot of crime just a few years earlier.

LAKSHMANANAll right, Khalil, I want to turn to you and ask what you think needs to be done to improve police relations with the communities they serve. And how is this going to play into trends in crime in the coming decade or two?

MUHAMMADThat's a really great question. I think we have to start with a fundamental understanding of the history of policing in this country. So every police department in America ought to be educated on the history of policing because it's not a pretty story, but in knowing the details of that story, as it was enacted between Irish-Americans and Italian-Americans, with Irish beating up on the Italians, I mean this is not just about black and white. This is about policing in America being a form of social control to keep poor people in their communities.

MUHAMMADSo the notion that policing by definition is free of this history is going to guarantee that this history keeps repeating itself. So that's number one. Number two, the only way that communities that need policing from the standpoint of dealing with people when they do harm to others, which is not the only way to deal with them, but let's be frank, in those communities where people are victimized, they want the state to respond.

MUHAMMADWe heard it from the caller. Police officers have to go into those communities and serve and protect those communities with the same courtesy and treatment that we expect everyone to receive, particularly in affluent communities. That's not happening, and the federal lawsuit Floyd versus New York revealed that just in New York alone, stop and frisk was not just a crime preventive policy, it was a way of systematically bullying communities of color and particularly young, black children in the city.

MUHAMMADAnd if we don't own that history, then we're going to keep putting a blanket over police officers, as if the system itself wasn't rigged from the beginning. I think the last thing is we have to fundamentally punish bad policing. It has to be punished with the same vigor and commitment to justice as we do when we go after people who have committed crimes. It's not an accident that in 1935, a Harlem Riot Commission report identified the need to hold abusive and criminal behavior among police officers just as much accountable as anything happening among citizens.

MUHAMMADThe Kerner Commission revealed the same conclusion in 1968, and yet today we're still having a debate about whether police officers can be held accountable in American society.

LAKSHMANANAll right, Barry, quickly in one minute, we're close to the end here, I want to ask you, obviously the spotlight has been on police who have engaged in misconduct, and a lot of this has obviously been videotaped from Ferguson and onward, this has put police and law enforcement in general under the microscope. What do you see as the risks, if any, to the bipartisan moves towards criminal justice reform?

LATZERThe biggest problem in policing is how to police minority communities, which are also high-crime communities, without creating very problematic conflicts between police and those communities. And this problem is not going away so long as these communities remain high-crime communities. Police have to respond. Police have to even perhaps over-police those areas, and of course there are resentments among people living there.

LATZEROn the other hand, there's no escaping this because the police have to continue to work in communities that are high-crime communities.

LAKSHMANANAll right, Paul Butler, last word to you. What in your view specifically can law enforcement and government be doing to continue the positive downward trend in violent crime?

BUTLERSo President Obama has talked about the need for police officers to stop acting like warriors in the community and acting like the people who they are supposed to serve and protect are the enemy and rather act like guardians so think of themselves almost as social workers. Their job is to keep families and communities safe and whole. And so if you think about that mindset of being a guardian, rather than a warrior, it calls for a whole different kind of person who even wants to be a police office.

BUTLERIt's somebody who is concerned about the community and sees ways of respecting communities and families, other than just by sending folks to jail.

LAKSHMANANAll right, Paul Butler, professor of criminal law at Georgetown Law School, Barry Latzer, emeritus professor of criminal justice at John Jay College of Criminal Justice and author of the new book "The Rise and Fall of Violent Crime in America," and Khalil Muhammad of the Schomburg Center for Research in Black Culture. Thank you all so much for joining me. I'm Indira Lakshmanan, sitting in for Diane Rehm, and thank you all so much for listening.