De-prosecution policy associated with rise in homicides in American cities

De-prosecution, a discretionary decision not to prosecute certain criminal offenses regardless of the evidence, has become an increasingly popular criminal justice strategy in the United States. A new study examined whether the application of a de-prosecution policy affected the number of homicides in large U.S. cities, using Philadelphia as a test case. The study found a causal association between de-prosecution and a rise in homicides.

The study, by a former prosecutor and academic researcher, appears in Criminology & Public Policy.

"As policies such as de-prosecution are being implemented across the United States, they should be tested for downstream results, especially those that are unanticipated or unintended," says Thomas Hogan, who conducted the study. "Calls for less prosecution under the guise of social justice may inadvertently lead to more homicides of minorities, which degrades social justice." Hogan has served as a criminal defense lawyer for a large international law firm, a federal prosecutor, and an elected district attorney.

De-prosecution can take place at multiple points in the criminal justice system: pre-offense, charging, pre-trial proceedings, or sentencings. Philadelphia presents a natural experiment to explore the impact of the policy: From 2010 to 2014, the Philadelphia district attorney's office maintained a consistent and robust number of prosecutions and sentencings. From 2015 to 2019, the office engaged in a systematic policy of de-prosecution for both felony and misdemeanor cases, with an emphasis on de-prosecuting drug possession, drug trafficking, and felony possession of firearms.

Hogan reviewed descriptive statistics for prosecutorial and homicide trends in Philadelphia from 2010 to 2019, comparing periods before and during de-prosecution. He then used a synthetic control method to compare homicide data from 2010 to 2019 in the 100 largest cities in the United States, using Philadelphia as the treatment city. The study included a quantitative classification of the prosecutors' offices in those 100 largest cities based on their prosecutorial policies.

The study found that de-prosecution was associated with a statistically significant increase of 74.79 homicides per year in Philadelphia from 2015 to 2019. This accelerated to more than an additional 100 homicides per year by 2018 and 2019 as the de-prosecution policy was used more robustly. Homicide victims were overwhelmingly people of color living in the poorest sections of the city.

From a statistical, mechanical, and theoretical perspective, the substantial drop in successful prosecutions for felony weapons violations appears to have been the strongest driver of this result. While no two cities are exactly the same, the de-prosecution hypothesis held across different locations, police departments, environmental conditions, and other background factors. The study intentionally excluded the years 2020 and 2021 to avoid any measurement issues associated with the COVID-19 pandemic or the murder of George Floyd.

Among the policy implications of Hogan's findings, the author suggests that prosecutors across the United States review the relationship between de-prosecution and homicides in exercising their prosecutorial discretion. In so doing, they might seek to determine the optimal volume of prosecutions to keep the number of homicides to a minimum, which he called the prosecutorial sweet spot.

In addition, citizens in cities that elected progressive prosecutors need to weigh the value of the de-prosecution policies against the possibility that such policies could boost homicides in their communities, especially homicides of minorities and low-income people.

Another policy implication is the budgets of cities in which de-prosecution is occurring. Not only may local district attorney's offices need less money (because they are prosecuting fewer cases), but there are also budgetary considerations for prisons, police, and public defenders.

The study was an outgrowth of research conducted by Hogan while studying criminology at the University of Pennsylvania, guided by the professors and teaching assistants in the criminology department.