A STUDY EXAMINING the effect of declining to prosecute lower-level nonviolent offenses — a signature policy adopted by Suffolk District Attorney Rachael Rollins that has drawn both praise and scorn — suggests the approach leads to significantly less future involvement by those defendants in the criminal justice system.

The new study, which looked at cases handled by the Suffolk County DA’s office going back to 2004, found that those defendants not prosecuted for lower-level misdemeanor cases were 58 percent less likely to face a criminal complaint over the following two years than those who faced prosecution for similar charges. 

The analysis, which is the first of its kind to rigorously evaluate a policy being embraced by reform-minded prosecutors across the country, provides striking evidence that steering defendants, particularly first-time offenders, away from prosecution and a criminal record can reduce their chances of cycling back into the legal system. 

The findings, being released on Monday by the National Bureau of Economic Research, are likely to bring heightened attention to the question of how best to deal with lower-level offenses, an issue that has become a controversial topic among law enforcement officials and advocates who say prosecution of these cases exacts an enormous toll on poor and minority communities without enhancing public safety.

Rollins put the issue front and center in her 2018 campaign, vowing to approach 15 nonviolent misdemeanors, including trespassing, shoplifting, receiving stolen goods, and drug possession with intent to distribute, with a presumption against prosecution. She and other reform advocates have argued that the legal system sweeps up too many people for misdemeanor offenses, cases they say result in a cascading set of negative consequences that can trigger repeated involvement in the criminal justice system.

Until now, however, there had not been firm evidence to support the turn away from prosecution.

“We think this is pretty compelling evidence of beneficial effects from not prosecuting,” said Anna Harvey, a professor of politics at New York University, who led the research along with Amanda Agan, an economist at Rutgers University, and Jennifer Doleac, an economist at Texas A & M University. 

The higher rates of new criminal complaints among those who did face prosecution for lower-level charges, on the other hand, mean “we may in fact be undermining public safety by criminalizing relatively minor forms of misbehavior,” write Harvey and her colleagues.

Rachael Rollins addresses reporters following her swearing in on January 2, 2019, as Suffolk County district attorney. (Photo by Michael Jonas)

In the new study, the researchers combed through all misdemeanor cases in Suffolk County from 2004 to 2018. The challenge was to figure out a way to compare defendants who were prosecuted and not prosecuted in a way that would get at the actual effect of the prosecutors’ decision. The problem in such a study is that the two groups are likely to differ in important ways that already affect their likelihood of facing another arrest, with prosecutors, for example, presumably targeting higher risk defendants for more aggressive treatment. 

For the bulk of nonviolent misdemeanors, the frontline assistant district attorneys handling cases over the 15-year span tended to be in broad agreement about whether to go forward with prosecution or dismiss the case. The researchers zeroed in, therefore, on the roughly 10 percent of cases where there tended to be wide variation in how assistant DAs handled cases with similar profiles. This was the closest they could come to approximating a true experiment in which subjects were randomly allocated to prosecution or non-prosecution. 

For these roughly 6,700 “marginal” cases, whether a defendant faced prosecution or not was not a function of the facts of the case or their background but of “the luck of the draw,” as Harvey put it, referring to whether the case was handled by a more lenient or less lenient assistant district attorney. 

Among these cases, not only did those not facing prosecution have less than half the chance of a new criminal complaint as those whose cases were pursued, the number of violent offense charges faced by this group within two years was 64 percent lower than for comparable defendants who faced prosecution. All told, 24 percent of those not prosecuted faced arrest again within two years compared with 57 percent of those who had been prosecuted for a similar charge. 

The paper says non-prosecution appeared to have a much larger impact on subsequent arrests for first-time offenders than on those with a prior record, “suggesting that averting initial entry into the criminal justice system has the greatest benefits.”

Harvey, who directs the Public Safety Lab, a research center at NYU, said the finding on first-time offenders is consistent with a phenomenon sometimes referred to as “the garden of forking paths.” If the goal is to avoid future involvement in the legal system, “if you’ve already gone down the wrong fork a number times, encountering another fork won’t take you back to the other side of the garden,” she said, referring to the effect of not prosecuting repeat offenders. “But if you haven’t encountered a fork yet,” she said of first-time offenders, “taking one of them keeps you out of the system.” 

At a time of increased scrutiny of racial disparities in the criminal justice system, the paper points out that reducing the prosecution of nonviolent misdemeanors in Suffolk County would “disproportionately benefit” benefit black residents, since they account for 46 percent of nonviolent misdemeanor cases but only 24 percent of the county’s population.  

Even for cases that don’t result in incarceration, the authors say prosecution of nonviolent misdemeanors can harm a defendant’s employment status in various ways that may make reoffending more likely. The misdemeanor cases they studied took an average of 185 days to be resolved, so those who were prosecuted faced numerous court hearing dates that may have disrupted their employment and income. A conviction, the authors say, may further hurt defendants’ “labor market prospects,” as will an entry in the state’s criminal records system, something that is much less likely with cases that don’t go forward past the day of their scheduled arraignment. 

Although the study has significant implications for Rollins’s policy regarding lower-level cases, the main analysis looked at the effect of not prosecuting cases over the 15-year period before Rollins took office. That underscores something Rollins has emphasized in the face of criticism of her do-not-prosecute list: The DA’s office under her predecessor, Dan Conley, often made a similar decision not to prosecute lower-level offenses. 

“We have to give credit — DA Conley was doing this,” she said. “He just wasn’t as vocal about it as I was, and we’ve increased it a bit as well.”

Former Suffolk DA Dan Conley. The office also chose not to prosecute lots of low-level misdemeanor cases during his tenure. “He just wasn’t as vocal about it as I was,” said Rollins. (Photo by Michael Jonas)

At the time of Rollins’s election, some police union leaders voiced concern about her no-prosecution policy pronouncement. Michael O’Keefe, the longtime district attorney for the Cape & Islands, wrote an op-ed in the Globe castigating “social justice” DAs, including “here in Boston,” for saying entire categories of crime won’t be prosecuted. 

Despite concerns that Rollins would sweep away charges against anyone arrested on one of the 15 crimes on her list, she appears to be overseeing more of a prosecutorial evolution than revolution. 

Harvey and her colleagues were able to conduct a more limited analysis of cases handled during the first eight months of Rollins’s tenure, starting in January 2019. They found that non-prosecution of nonviolent misdemeanors, including those on her list of 15 offenses and not on it, increased by 5 to 8 percentage points, or by 15 to 20 percent, compared with Conley’s last year in office, when 34 to 38 percent of those cases were not prosecuted. (The study found no increase in non-prosecution of nonviolent felonies under Rollins.) 

The increases in non-prosecution under Rollins appeared to also lead to decreases in new criminal complaints over the following year, suggesting her expansion of the cases handled this way is having an effect similar to that of cases not prosecuted in the 15-year period before she took office when Conley was DA. 

The study said it’s possible that a falloff in subsequent criminal complaints against those who were not prosecuted could come simply from a reluctance of police to make arrests if they believe a case won’t be prosecuted. But the fact that police don’t usually know an individual’s full criminal history when faced with an arrest decision, and that the effect was seen over the long span of time before Rollins’s high-profile policy was in place, support the conclusion that those people are in fact committing fewer offenses.

“We think it’s suggestive that we are really seeing reductions in reoffending, not just in law enforcement response to reoffending,” said Harvey. 

The authors say it’s also possible that Rollins’s policy could drive up crime rates if would-be offenders think they won’t face sanctions. Harvey said the study wasn’t able to address that question definitively, but the paper noted that crime rates for the nonviolent offenses on Rollins’s list continued to decline in Boston during her first year in office. 

Rollins said the study results should be used to bolster support for community programs to address mental health and substance use disorder, which she says are the driving forces behind lots of nonviolent misdemeanor offenses. 

“It’s remarkable, and we need to be screaming this from rooftops,” Rollins said of the study findings. “I hope what this results in is a reallocation of resources,” said Rollins, who said she wants to see more services for those who need help and greater law enforcement effort directed toward tackling violent crime. 

Sgt. Det. John Boyle, a spokesman for the Boston Police Department, said the department had not had time to read and comment on the 87-page study, which it only received late Friday.   

Alexandra Natapoff, a professor at Harvard Law School who has extensively studied the prosecution of misdemeanor offenses, said the study “gives empirical teeth to just how costly and counterproductive low-level misdemeanor arrests and court criminal convictions can be.” Natapoff, author of the 2018 book Punishment Without Crime: How Our Massive Misdemeanor System Traps the Innocent and Makes America More Unequal, said we have paid far too little attention to the harmful impact on individuals and communities of prosecuting misdemeanors, which account for 80 percent of all criminal cases in the US. 

“These cases that we treat as chump change, in fact, are destroying lives, and destroying families, and undermining the economic wellbeing of communities thousands of times over every day,” Natapoff said in a recent video explainer on the reach of misdemeanor convictions. 

Miriam Krinsky, executive director of Fair and Just Prosecution, a group formed in 2017 to work with reform-minded DAs, called the study an affirmation of the changing approach to prosecution underway in a number of major cities. “We are seeing a new normal among elected prosecutors who, like DA Rollins, share a view that we have prosecuted too many individuals who can be better addressed by treatment or support through a public health lens,” she said. “It’s incredibly significant to see research like this that proves the value of the new thinking and the paradigm shift that’s taking place.” 

Harvey said she had been eager to study the impact of not prosecuting low-level offenses, but had difficulty finding a DA willing to grant her unfettered access to their data. She approached several DAs in recent years who had embraced the policy of reduced prosecution of misdemeanors but then balked when it came to giving her full access to their county’s data. 

Harvey said she met with Rollins only a couple of weeks after she took office in January 2019. “I said, ‘Rachael, I can’t promise that the results are going to be supportive of what you’re doing,’” Harvey recalled. “She signed the data use agreement that day. She said, ‘look, I want to know the truth. I don’t want you to sugar coat it.’”

Rollins, who has ruffled some feathers with her blunt approach, said she didn’t hesitate before agreeing to the study.

“I said, yes, look at everything, don’t hold back, and tell me what you find,” said Rollins. “And then we’re going to be really transparent about the outcome. So this is a good outcome for us. But I need you to hear — if it was not, we would have said this doesn’t appear to be working.”