It’s usually taken as a given in the United States that the power to prosecute criminal cases belongs exclusively to the government. Justice Clarence Thomas employed this reasoning in his concurrence in Trump v. United States (2024), the landmark Supreme Court decision that greatly expanded presidential immunity. Referring to the appointment of Jack Smith as a special counsel to investigate Donald Trump’s alleged crimes during his first term in office, Thomas wrote that “a private citizen cannot criminally prosecute anyone, let alone a former President.”
Professor Emma Kaufman disagrees. In a new article, “The Past and Persistence of Private Prosecution,” published in the November 2024 issue of the University of Pennsylvania Law Review, Kaufman traces the largely forgotten history of private prosecution in the US, demonstrates that private prosecution still exists, and suggests how this ongoing phenomenon might help change the conversation about how to reform a broken criminal justice system.
Kaufman has taught about the origins of the public prison system and also has studied the history of public police forces, both of which originated in the 19th century. She was also familiar with contemporary debates about the privatization of both entities. But she realized a few years ago that she knew little about the genesis of a third component of the criminal justice system: the public prosecutor.
“When did the public prosecutor become a taken-for-granted part of the criminal justice system?” Kaufman asks. “And can you outsource this [function]? Because you can outsource other parts of the system…. I was curious about filling out the institutional picture of the criminal legal system.”
The idea that criminal law is properly classified as public law—because crimes affect the entire community—dates back at least to Roman law. But it didn’t start to become a truism in US law until the late 19th century, Kaufman discovered. Private prosecution was widespread in the US up to that time. For instance, the widely publicized 1850 murder trial of Harvard professor John White Webster, prosecuted by a private attorney, resulted in conviction and hanging. As a lawyer in Illinois before becoming president, Abraham Lincoln prosecuted rape and murder cases.
What led to the shift? Expansion of the franchise in multiple states facilitated the popular election of more public officials, including public prosecutors, Kaufman writes. Almost three-quarters of states elected criminal prosecutors by 1860, increasing their prominence as public officials. Shortly thereafter, a wave of state court rulings began to tout the primacy of public prosecutors over private ones.
Kaufman’s article offers two potential explanations for what fueled the shift to the idea of a government monopoly on criminal prosecution. It might have been a reaction against rampant cronyism in government—the courts were ruling that parties with a financial interest in a case could not prosecute it—or it could have been a result of the crime problems arising from rapid urban growth. “The theme that runs through these stories is that in the late 1800s, public prosecutors came to be viewed as impartial officials, and, as a result, as the only actors with the right disposition to exercise criminal power,” Kaufman writes.
At the same time, public police forces were proliferating during this period, as were early penitentiary systems. “The prosecutor’s monopoly on criminal charging power cemented the police as the primary enforcers of criminal laws and the prison as a palatable remedy for violations of the criminal code,” Kaufman explains.
The idea of a government monopoly on criminal prosecution facilitated two major conceptual shifts in criminal law, according to Kaufman’s article. The first was prosecutorial immunity. The regulation of criminal power through malicious prosecution claims, regularly employed against private prosecutors, gave way to the thinking that public prosecutors were quasi-judicial officers who needed immunity to pursue their mandate fully. The second shift was a new theory of standing. The previous notion that any citizen had an interest in pursuing a criminal case in the interest of public order gave way to the thinking that only public prosecutors could do so.
Yet private criminal prosecution in the US has never really gone away, Kaufman argues. It’s still legal in seven states for a non-state actor to initiate and litigate a criminal case. (In Oklahoma, for example, anyone who objects to open adultery, which is a crime in that state, can initiate a prosecution—not just the affected spouse.) And in those states and 20 more, private prosecutors can appear alongside public ones, prosecute cases with a district attorney’s approval, or present directly to grand juries.
Many of these states limit private prosecutors to lesser criminal offenses and lower courts. (Pennsylvania, where private prosecutors can pursue any crime and obtain felony indictments, is a notable exception.) The prevalence of private criminal prosecution is far greater when it comes to government outsourcing of criminal prosecution to lawyers in private practice acting as an extension of the state.
While such arrangements are not uniformly or well documented across all jurisdictions, Kaufman used a mix of typical and less conventional sources—“statutes, cases, ethics opinions, contracts, minutes from city council meetings, news reports, law firm websites, interviews, and any other relevant source [she] could find”—to find conclusive evidence of contract prosecution in 31 states, although the practice is likely even more ubiquitous. Prosecution-by-contract is used largely for lesser crimes, but by no means exclusively, Kaufman notes—particularly in rural areas where public prosecutors are not cost effective. In some Montana towns, private firms handle all criminal prosecutions. Contract prosecutors litigate felonies in Idaho’s two largest jurisdictions.
“Governments also outsource prosecution to manage controversy and expand state capacity,” Kaufman explains in her article. “Some municipalities outsource the prosecution of sex crimes and crimes committed by police to avoid the political and financial strain of ‘complex’ cases.” In Georgia and Louisiana, death penalty cases are outsourced. “Prosecution contracts explicitly shift criminal power, including charging discretion, to private individuals,” Kaufman writes.
The statistics Kaufman has gathered paint a striking portrait. She notes that, under current law, about three-quarters of the nationwide criminal docket can be prosecuted privately in some manner. Even when lesser offenses are excluded from the count, more than half of US felonies and misdemeanors could be handled by private prosecutors. “The criminal legal system tolerates much more private prosecution than the state monopoly narrative implies,” Kaufman writes.
What are the implications of the contradictions and complexities Kaufman has uncovered in tracing the neglected history of private prosecution in the US? For one, it provides a caveat to Justice Thomas’s claim that “a private citizen cannot criminally prosecute anyone, let alone a former President”—not to mention Judge Aileen Cannon’s dismissal of Trump’s indictment involving possession of classified documents on the grounds that the special counsel’s appointment was unlawful, Kaufman contends. Both jurists’ claims stem from conservatives’ unitary executive theory, which asserts that criminal prosecution is an executive power. A more nuanced view of private prosecution weakens those arguments. On the flip side, liberal protests against the privatization of criminal justice are also undermined in the absence of a strict government monopoly.
“Public and private enforcement have always coexisted in the criminal legal system, even when it comes to criminal charging power, allegedly the heartland of state control over criminal law,” Kaufman writes. “Once that reality becomes clear, the current debate over privatization starts to seem like it is limiting the options for criminal procedure and foreclosing more nuanced conversations about what it means to have a legitimate system of criminal law.”
Kaufman doesn’t take a strong normative position on how to improve American prosecution practices, although she mentions some possibilities that a more nuanced dialogue might open up. Prosecution could become truly, fully public. It could also look more like public defense, with multiple private providers competing for municipal contracts, thus spurring incentives for quality and innovation.
“Once you see how varied the actual models for prosecution are in the United States beneath the surface, you start to have a really robust debate about the best institutional design to try to tame some of the harshness and unfairness of the criminal justice system,” says Kaufman. “And I don’t yet have the answer about which of those models is going to produce the best outcomes, but I think that’s a really exciting place for us to start.”
Posted February 28, 2025