Current Projects


Prosecutorial Reform Initiative

Prosecutors play a vital role in the criminal justice system. After an arrest, prosecutors have numerous choices to make regarding whether and how to pursue prosecution of an offense. In many jurisdictions, prosecutors use this discretion to pursue prosecutions of subfelony violations to the full extent of the criminal law. In these jurisdictions, cases involving subfelony offenses typically consume a large share of law enforcement, prosecutorial, and judicial resources. Yet it is unclear whether the aggressive prosecution of subfelony offenses actually reduces offender recidivism; the practice may actually result in increased recidivism, and/or the escalation of minor offending into more serious offending. Some prosecutors’ offices, however, are pursuing reforms that implement alternatives to prosecution, or that reduce charging, bail recommendation, and/or sentence recommendation practices for defined categories of subfelony offenses. Working with multiple district attorneys’ offices, the Lab’s social science and engineering teams are investigating the impacts of these reforms on offender recidivism, and designing and experimentally testing a decision assist tool to nudge prosecutors’ decisions in the direction of reducing reoffending.

Jail Data Initiative

The problem of overincarceration has received considerable attention of late. The focus of this attention, however, has largely been on state and federal prison systems. Often overlooked are local jails. In any given year, approximately 11 million Americans will be detained in a county jail, often because they lack the funds to post bail, or even because they lack the funds to pay their fines. Yet we know little about county jail practices, including which counties are systematically jailing defendants pre-trial and/or post-fine, and about the consequences of these practices. It is possible that longer periods of pre-trial detention, for example, actually increase recidivism, and/or escalate petty offending into more serious offending. Through the generous support of Arnold Ventures, our data science team is crawling daily county jail rosters and criminal case records in over 1,000 counties. Using these data we will be able both to identify counties that are systematically jailing defendants pre-trial and/or post-fine, and to estimate the impacts of these practices on recidivism.

911 Response Analytics

Calls to 911 in large urban jurisdictions are typically first assigned to a responding service (e.g., police, medical, fire), and are then assigned priority codes determining the speed and nature of the service's response. These human-assigned call and priority codes may not be optimal. For example, calls involving mental health and substance abuse issues may be assigned to policing agencies when they might more appropriately be assigned to medical professionals. Calls involving behavioral health issues assigned to policing agencies may or may not be assigned codes providing for response by officers trained in crisis intervention. Call taker biases may affect the assignment of call and priority codes. Working with a large urban policing agency, we are exploiting the as-if random assignment of 911 calls to call takers to evaluate the causal effects of call taker discretion on the assignment of call and priority codes, and subsequently on call outcomes, and to design call response protocols that may reduce the risks of escalated encounters.

911 Response Field Experiment

Many policing agencies seek to improve their relationships with the communities they police, yet struggle to find effective means to do so. Working with a large urban policing agency, we are developing a randomized controlled trial of a platform that pushes an SMS-based survey to recent 911 callers, asking them to provide feedback on how they were treated by responding officers. Responding patrol officers may then access their average survey ratings, as well as those of the other officers in their unit, through a web-based interface. The platform may both incentivize responding officers to treat 911 callers with greater professionalism, and increase caller satisfaction with the police response to their call. More generally, the platform may provide an effective means for agencies to receive real time feedback from the communities they police.

Identifying Sex Trafficking

Sex trafficking is a crime of extraordinary violence. Its frequency is likely severely underreported, given the isolation within which its victims are kept. Working with a multi-university team, we are extracting structured content from a very large corpus of online commercial sex ads and provider reviews crawled over a period of several years, and integrating this content with law enforcement records on sex trafficking cases. We are then looking for features in the ad and review data that are predictive of the presence of sex trafficking, and that may assist law enforcement agencies in identifying newly posted ads and reviews associated with trafficking. We are particularly focusing on urban school district calendars, which typically include days when high school-aged children are not in school, but adults (including teachers) are at work. Initial results suggest that school calendars may be a good predictor of the incidence of sex trafficking, highlighting for agencies the importance of investigating online sex ads posted on days when high school-aged children are not in school, but adults are at work.

Criminal Appeals Equity Project

Existing work has indicated that competitive partisan elections appear to induce more anti-defendant rulings, relative to other judicial retention institutions. This work has led many to advocate against the use of partisan elections for judicial selection and retention. Yet existing work has been constrained to cross-judge estimates, limiting the ability to draw causal inferences. In New York State, intermediate appellate judges must be elected, and re-elected, in contested partisan elections in order to be eligible for gubernatorial appointment, and reappointment, as Appellate Division judges. Using content extracted from the crawled text corpus of the approximately 38,000 slip opinions in criminal appeals heard by New York State's intermediate appellate courts between 2003-2017, and defendant demographic and crime data crawled and extracted from the New York State Department of Corrections' inmate database, we find that impending reappointment induces more rulings against black defendants, but not against nonblack defendants. We find no additional effect of impending reelection on appellate judge votes in criminal appeals.

Detecting Domestic Violence

Domestic violence is both distressingly common and significantly underreported to law enforcement authorities. Its widespread presence is costly to its victims, to their children, and to society more generally. Yet there may be strategies to assist both law enforcement and social service agencies in detecting and addressing the presence of unreported domestic violence. For example, we know that the timing of reported domestic violence responds to the timing of the distribution of social benefits. In partnership with NYU Wagner’s Policies For Action Health Hub, and leveraging the randomly assigned timing of the distribution of social benefits to individual households, we are working with New York State’s Medicaid data to identify female and child injuries that may be due to unreported domestic violence. We are then looking for features that may help to explain both the incidence of domestic violence, and its relative underreporting.

Policing for Revenue

There is widespread concern about the deployment of law enforcement resources to generate revenue for fiscally stressed jurisdictions. Yet rigorous evidence of the practice has been elusive. Working with data sourced from a large regional highway patrol agency, we are exploiting a discontinuity in the allocation of revenue received from traffic citations to explore the consequences of fiscal incentives for both law enforcement and driver behavior. In our initial analyses, we find that traffic safety enforcement increases in the towns wherein the regional government receives more citation revenue, leading to increases in roadway safety in the high-revenue jurisdictions, but decreases in roadway safety in the low-revenue jurisdictions. We also find that these fiscal incentives have negative economic consequences for cited drivers in the high-revenue jurisdictions, leading to increased late payment of fines, and greater exposure to penalties for late payment.

Diversifying Policing

Recent events have directed renewed attention to the question of whether increasing the proportion of nonwhite officers in law enforcement agencies would lead to different public safety outcomes. Increasing the proportion of nonwhite police officers may lead to an increased acceptance of policing in nonwhite communities, fewer instances of the use of force, and fewer citizen complaints, leading in turn to increases in the reporting of crime and in the willingness of civilians to cooperate with police investigations. Nonwhite officers may also exert greater effort, or be better equipped, to clear crimes in largely nonwhite communities. Working with both survey and law enforcement administrative data, we are investigating the impacts of police force diversity on public safety outcomes.