While juries convict and judges pass sentence, it is the elected local prosecutor—the district attorney (DA)—more than any other actor who determines the course of criminal justice in the United States. The decision on whether to charge an individual, what charges to file, whether to drop a case or offer a plea bargain--and the specific terms of that bargain--are unreviewable powers of district attorneys. In this episode of the Harvard Horizons podcast, PhD student Chika Okafor explores the dramatic effect that electoral politics have on the sentences DAs seek in criminal cases. 

This transcript has been edited for clarity and correctness.

Let's turn the clock back to the end of the 20th century, to the 1980s and 1990s, to the time period when many elected officials fought to be viewed as tough on crime. This time period coincided with the war on drugs, with the crack cocaine epidemic, with the rapid expansion in the US prison population by over 600%. From 200,000 in 1974 1.3 million in 2000. 

Against this backdrop of rising incarceration, local prosecutors represented one of the most influential actors in the US criminal justice system. Sometimes called district attorneys or DAs for short. Local prosecutors had nearly unfettered authority on whether or not to charge a suspect with a crime, as well as on the crime to charge them with. They are also a key factor in plea bargaining. 

Despite what we learn from TV shows, the vast majority of people convicted of crimes never saw a judge, nor a jury trial to determine guilt. Instead, they pled guilty, with the terms of their plea deal brokered by the prosecutor. In a district or county, the DA leads the entire prosecutor's office. And in these offices, DAs set the tone, they set the culture, they set the policy. And in nearly all US states, DAs are elected. 

Given the fact that DAs are elected, and given their extreme influence over the US criminal justice system, I set out to understand whether DAs were also influenced by this desire to be viewed as tough on crime during this period in our nation's history. This period of rising incarceration. Did DAs respond to political incentives? Were more people put behind bars? Did we collectively deviate from Justice? 

I am a trained lawyer. I am also an economist trained in the PhD program here at Harvard, and so I use the tools of economics, modeling, econometrics to explore foundational matters of justice, with one area being criminal justice. To embark on my study, I first collected data from the National Corrections Reporting Program, which includes millions of convictions at the height of the rise in incarceration. 

I then compiled a new comprehensive data set on the political careers of all DAs in office during this period in our nation's history from roughly 1986 to 2006. As a scholar in law and economics, I then applied a sophisticated econometric model to this criminal justice data. In doing so, I found that the level of criminal sentencing increased leading up to the timing of the DA election, which is the dashed vertical line on the graph. 

This graph will show property offenses, and the units are in log points, which approximates a percentage change relative to the time period two years prior to a DA election. Each dot represents an estimate for the corresponding month, and the blue line approximates the best fit of the overall trend, which shows an increase in sentencing leading up to the DA election. 

Now, when we look at all criminal offenses bundled together, we see a similar trend persists. For both the admissions rate and the total month sentence per capita, the level of sentencing increases leading up to the timing of the DA elections. Now, this analysis suggests that there's a relationship between the timing of the elections and the level of criminal sentencing, which suggests that DA practices may be responding to public sentiment. 

What I next set out to understand is whether the level of criminal sentencing is related to the public's racial sentiment in a particular county. This map shows an estimate of the pro-white racial bias by county based on something called the IAT assessment. Darker red areas correspond with more pro-white racial bias. My goal is to understand whether the level of psychological racial bias within a county is related to the racial bias in sentencing throughout the county. 

In the 1990 US population, the ratio of white to Black members of the population was 7 to 1. Yet, when it comes to the prison population, the ratio of white to Black prisoners was seven to seven or one to one. So in short, there were disproportionately more Black prisoners. 

Now, let's take these seven prisoners and assume they relate to the lowest levels of pro-white racial bias. What I find is interesting. Although I find no relationship between pro-white racial bias and the volume of white prisoners admitted to prisons, this is not the case for Black prisoners. 

The greater the pro-white racial bias in the county, the higher the level of sentencing for Black prisoners throughout the entire election cycle, which suggests that the psychological bias within the county may be related to the racial bias in sentencing throughout the county. So now, let's look at the evolution of public sentiment over time. 

As I mentioned earlier, in the 1980s and 1990s, there was a lot more talk about and perceived benefit from being a politician who was viewed as being tough on crime. According to the General Social Survey, which is a survey that measures public opinion over time, only after about 1994 did the fraction of the population who viewed courts as not too harsh begin to decline. 

In short, there was an evolution in public sentiment over the last 25 years or so, with more people viewing the court system as being too punitive. Now, this downward trend in public sentiment maps closely with the downward trend in the election year effects on the admissions rate during the same time period, which is the graph at the top right. So again, there appears to be a potential nexus between public opinion and criminal sentencing. 

So much work on criminal justice reform to date has focused on improvement to the system itself and to the laws that govern it. Yet, my research suggests that focusing on hearts and minds, on shifting public opinion towards punishment may prove influential in shifting sentencing outcomes and stemming mass incarceration. Achieving progress is not merely the individual project of politicians, or policymakers, or even DAs. Rather achieving progress is a collective project of all of us, as citizens, as Americans. 

Our challenge as a nation is to balance the concern for safety and security with the acknowledgment of the humanity of all people, including the incarcerated. Only then will we move past the simplistic tough-on-crime rhetoric of yesterday, past the tragic dynamics of mass incarceration still evident today to a brighter future. A better tomorrow ripe not only with more safety and more compassion, but also with more justice. 

Harvard Horizons Podcast: The Politics of Justice