Joshua Lott / Reuters

The Supreme Court handed down a case in June, hidden among the end-of-term blockbusters, that created an important new constitutional protection against police violence. In Kingsley v. Hendrickson, the justices articulated a standard for judging the conduct of police officers accused of using excessive force on suspects being held in pretrial detention.

Justice Stephen Breyer, writing for the majority in a 5-4 ruling, found that whether the police intended to use excessive force was irrelevant. The standard, Breyer argued, should be whether a reasonable observer would view the use of police force as excessive. By taking this route, the Supreme Court departed from the extraordinary deference that the law traditionally gives police testimony. Preceded by a year of visceral imagery of black deaths caused by police violence, the decision in Kingsley reflects a widening rift between community and police perceptions of the legitimacy and appropriateness of police force.

In 2010, Michael Kingsley was being held in jail on drug charges as a pretrial detainee in Monroe County Jail in Sparta, Wisconsin. Kingsley had taped a piece of paper to the light cover above the bed in his cell. A deputy in the jail ordered him to take it down. The deputy complained to his commanding officer when Kingsley didn’t comply. Again and again, Kingsley refused to move the paper, and was issued a “minor violation.” Four police officers eventually forcibly removed Kingsley from his cell and carried him to a receiving cell where he was left in solitary confinement.

That much is undisputed; what followed next is less clear. Kingsley testified that a sergeant kneed him in the back, and that two officers then slammed his head into a concrete bunk. This caused him pain so severe that he couldn't immediately walk again. The jail officers, by contrast, said that Kingsley was resisting their efforts to remove his handcuffs. At this point Kingsley was handcuffed and lying face down. Both parties agreed that the officers finally ended the altercation by applying a taser to Kingsley’s back for around five seconds. Kingsley recalled an officer saying, “Taze his ass!” just before the electric shock.

The Eighth Amendment, which prohibits “cruel and unusual punishment,” only applies to prisoners who have already been convicted of a crime. The Fourth Amendment is generally interpreted to protect against unreasonable police actions against people prior to their arrest. Before Kingsley, people who had been arrested and detained, but not yet convicted, fell into a legal void.

To fill in the constitutional gap, Kingsley argued at trial that the officers’ use of excessive force violated his civil rights under the 14th Amendment’s Due Process Clause—one of the cardinal provisions of the Constitution. It forbids any state actor, such as a police officer, from depriving a person of “life, liberty or property without due process of law.”

The case turned on what instructions should have been given to the jury at trial level. Kingsley argued that the words “reckless” and “reasonable belief” had been repeatedly and improperly used in the jury instructions. The Court agreed. During oral argument, Justice Sonia Sotomayor observed that police officers seemed to want the authority to “get a free kick” when managing pretrial detainees. The Court’s decision makes it harder for police and corrections officers to get that constitutional free kick.

Kingsley marks a departure from a traditionally deferential posture to police testimony both inside and outside courtrooms. In the 1985 case of Tennessee v. Garner, the Court ruled that so long as police officers have a reasonable belief that his life or others are in danger, their use of force will likely be proportionate in light of the government’s interest in effective law enforcement. The Eighth Amendment bars only correctional force applied with “deliberate indifference,” or exercised “maliciously” or “sadistically” against inmates.

The less deferential holding in Kingsley supports research showing that ordinary citizens hold very different views than the police on the perception and tolerance of abuse of force. A recent study of 3,230 sworn officers in 30 American police departments showed that new or novice officers were more likely to view excessive force as worthy of severe discipline than officers with a moderate level of experience. These newer officers were also more likely to report such incidents than their more experienced peers. This suggests a gap between the public and police perceptions of excessive force, a gap that widens with exposure to institutional culture.

From Ferguson to Freddie Gray, demonstrations of public outrage against police killings highlight a growing gulf between the police and citizens. There is some evidence that this anti-authority zeitgeist has also permeated the courtroom: Some prosecutors and defense attorneys concede that the events of the past year have taken a toll on police credibility on the witness stand.

Kingsley also serves as a timely reminder that many pretrial detainees are charged with nonviolent offenses, and that they are held in custody only because they are too poor to secure their release before trial. In 2008, fewer than 18 percent of non-felony defendants in New York City courts posted bail when it was set at $500. Only 11.3 percent of non-felony defendants posted bail when it was set at $1,000. The enduring correlation between poverty and race means that city and county jails are often filled with poor people and people of color.

Ultimately, Michael Kingsley stood up for the idea that police not only protect, but also serve, the public. They should be held to the standards of the people that they serve. At the end of its term, the Supreme Court championed that prevailing public opinion.

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