Computer Science Students Track Biased Policing, Inform NAACP Advocacy

Through a Mentored Advanced Project (MAP), Grinnellians Anthony Schwindt ’25 and Tanmaie Kailash ’24 are analyzing a growing dataset of traffic stops conducted by the Des Moines Police Department. Led by Assistant Professor of Computer Science Eric Autry, their work is helping Iowa civil rights organizations shed light on trends in racially biased policing.

In November, Autry, Kailash, and Schwindt were even invited to present the early findings of their research at the 11th annual Iowa Summit on Justice and Disparities.

The Need for Data

Autry, a Des Moines area native, believes in using data analysis to address systemic bias in society. For years, he has regularly attended the Des Moines NAACP Legal Redress Committee. In addition to advocating for legal practices that expand civil rights, the committee’s work includes the pursuit of just and non-discriminatory policing.

It’s a crucial pursuit, Autry explains; Iowa has no ban on police racial profiling or pretextual stops — stops based on “reasonable suspicion of criminal activity.” Nothing prevents racial bias from influencing an officer’s decision to pull someone over, issue a citation, or make an arrest.

Leading civil rights organizations have long put pressure on Iowa legislators to pass laws requiring data collection for citations and arrests, explains Autry. “Despite people’s experiences of biased policing in the Des Moines area, we’ve lacked the hard data to back that claim.”

Spearheaded by the organization Just Voices Iowa, the push for police data collection was finally fruitful in 2016, and the Polk County Police Department began to document every traffic stop conducted by its officers. Just Voices gained access to the data, but it sat largely unexplored for several years — too messy and unwieldy for anyone but trained data scientists to work with.

Then, in summer 2023, Autry sought MAP students to help him unravel the dataset.

Invested In Change

Having grown up in the Des Moines area, Anthony Schwindt ’25 was drawn to the racial profiling project by its relevance to his own experiences with policing in Iowa. “It’s an important topic to me personally,” he explains. When he heard about Autry’s MAP, Schwindt jumped at the opportunity to work on research tangibly affecting his home community.

Meanwhile, Tanmaie Kailash, a computer science and sociology major, was looking to get involved in research with social impact beyond the scope of academia. “I am really interested in asking, ‘How can you harness technology to transgress against existing systems of power?’” Kailash explains. “Professor Autry’s research fit that description.”

Dramatic Disparities

Autry, Kailash, and Schwindt spent much of the summer of 2023 getting the data into a clean enough form to work with. “It is an incredibly messy, real-life dataset,” Kailash explains. “Because it’s police data, lots of individuals contribute to the dataset, and the way that they collect data can change over time.”

But when it was finally ready to be analyzed, the dataset immediately began to reveal stark trends. Black individuals were consistently overrepresented in traffic citations — receiving citations one and a half times as frequently as would be expected based on their makeup of the overall Des Moines population.

“And when we looked at arrests, the overrepresentation of Black individuals became even more dramatic,” Autry asserts. Black drivers were not only more likely to be stopped by police, but the outcomes of those stops were of greater consequence, leading to higher numbers of both citations and arrests.

Autry, Kailash, and Schwindt kept digging, discovering that Black drivers receive about two charges per incident while white drivers receive fewer. Next, Autry says, “We can start to ask, what are the penalties for these charges? How much money is coming out of this community? How much jail time are we seeing?”

When it comes to quantifying the consequences of racially biased policing, he and his students are just getting started.

‘Working Toward the Same End’

In the fall, Schwindt and Kailash presented their early findings at a meeting of the Des Moines area NAACP Legal Redress Committee. The committee was so interested in the research, they invited Autry’s team to host a workshop at November’s Iowa Summit on Justice and Disparities.

At the summit, their audience included national civil rights figures, city officials, police chiefs, lawmakers, Iowa Supreme Court justices, and even a U.S. attorney. None of these attendees were new to the idea of inequality in the criminal justice system, yet the data still floored them, Kailash recalls. “Even to these lawyers who've been working on civil rights issues for years, the magnitude of this issue is still shocking to see when it’s laid out like that."

“You just see a disproportionate rate of the Black population of Des Moines being completely overrepresented,” adds Schwindt.

The diversity of their audience at the summit required that Kailash and Schwindt adopt more inclusive approaches to presenting data. After all, for their analysis to be useful in informing real policy change, both their methods and their results must be broadly understood. “If research is to have social impact, you have to have diverse coalitions of people working toward the same end,” says Kailash. “So we need to make sure we’re reaching those people.”

Beyond Statistics

Schwindt and Kailash have continued their MAP with Autry during the academic year. In addition to decoding the penalties for each charge, they’re now working with the geocoordinates of every citation. Mapping traffic arrests will pinpoint areas of the city being overpoliced, they hope.

Their work is an incredibly direct application of data science. For them, it’s important to remember that the data aren’t just bar charts — the information affects real lives.

“Every point in this dataset is a human,” says Schwindt. “We sometimes have to stop our conversations and remind ourselves that these are individual people with individual stories, individual lives.”