In March 2020, police officers in Louisville, Kentucky, shot and killed 26-year-old Breonna Taylor when they invaded her home to search for an alleged drug dealer. The events that led to the innocent bystander’s death started with deception: Police officers made false statements to a judge to get the warrant. If not for those lies, Breonna Taylor might still be alive.

Police accountability and misconduct have received significant press in recent years, with particular focus on racial bias and excessive force. More people are paying attention, and that’s good. But the appallingly routine habit of police providing false testimony, both in written reports and on the witness stand, still doesn’t get enough attention.

This practice is so common that police officers coined their own word for it decades ago: testilying. Scholarly studies of police departments in the United States agree that the police lie, and regularly so, not just to suspects but to lawyers and judges too. In Chicago, where I was a public defender, courts have exonerated nearly 200 people since 2016 who were wrongfully convicted by officers who planted drugs, coerced people into testifying falsely and lied about their own abuses. In Minneapolis, where I now teach and work as a policing scholar, the initial police narrative after George Floyd’s murder in May 2020 noted that Floyd “appeared to be suffering medical distress” during the arrest, and omitted any mention of officers kneeling on Floyd’s neck.

This practice is outrageous. While police departments themselves bear substantial blame for tolerating deception, they are not the only responsible group. Two other key actors share responsibility for enabling this practice and have opportunities to prevent it: prosecutors and judges.

Many police forces have a deeply rooted us-against-them culture, where they see certain members of their community as criminal and will justify using whatever means necessary to “get the bad guy,” including falsifying affidavits and lying about how they obtained evidence.

In 1961, the United States Supreme Court adopted an exclusionary rule to the Fourth Amendment, which protects people from unreasonable searches and seizures. This rule prevents prosecutors from using evidence that police obtained in violation of the Constitution, such as an illegal search or interrogation. But instead of changing their behavior to fit this rule, many police officers simply changed their testimony. A 2000 study of more than 500 police officers in the New York Police Department concluded that perjury is “widespread” in policing; a 1990s survey of prosecutors, judges and public defenders in Chicago found that they believed police officers committed perjury as often as 50 percent of the time when testifying on Fourth Amendment issues.

Officers may consider these lies well-intentioned, helping to convict guilty people. But deception ignores legal rules, unfairly elevates police officers as the ultimate arbiters of guilt, and leads to tragedies like the conviction or killing of innocent people.

Many prosecutorial offices do a totally inadequate job of noting officer deception, tracking it and disclosing that information to defense attorneys. Sixty years ago, in 1963, the Supreme Court case Brady v. Maryland determined that prosecutors must disclose exculpatory evidence, which is information that suggests the accused could be innocent. Two later cases, Giglio v. United States and Kyles v. Whitley, clarified that exculpatory evidence includes information that could detract from the credibility of government agents, including police, and that prosecutors must establish procedures for tracking this evidence. People accused of crimes deserve to know if the officers involved in their arrest have a history of lying; judges, too, deserve to know how credible police witnesses are in their cases.

Because of this obligation to disclose exculpatory evidence, some prosecutors have created “Brady lists” of police officers with histories of misconduct, including deception. Yet while almost all prosecutors have at least heard of Brady lists, a 2019 study by USA Today and the Invisible Institute suggests that most still don’t keep them. Some can’t be bothered; others don’t know how or are worried about reprisals.

There are startlingly few legal mechanisms for forcing prosecutors to keep these lists: In 2021, Colorado became the first state to pass a law that mandates Brady lists and establishes procedures for what kind of information the prosecutors should track and how to track it. But it is the only state to do so. More prosecutors need to take seriously their ethical and constitutional obligations to track information about police deception.

Lastly, judges have enabled testilying by consistently deferring to police officer testimony and expertise. As Harvard legal scholar Anna Lvovsky has recognized, judges have a political interest in appearing “tough on crime,” and that may incentivize them to turn a blind eye to officer deception. A high percentage of US judges are former prosecutors, who have long histories of working with the police and may bring a bias against criminal defendants into their ostensibly neutral roles. Interestingly, recent trends may help to shift this. US President Joe Biden has purposefully tried to increase the diversity of the federal judiciary, hiring former public defenders or civil rights lawyers into roles traditionally filled by former prosecutors.

Growing concerns about officer misconduct may help to reduce the decades-long practice of testilying. But the issue is urgent. Breonna Taylor and hundreds of others who have suffered or died as a result of officers’ false claims deserve a legal system and society dedicated to ending this practice.