Bryan Kohberger’s defense team is opposing the death penalty for the quadruple Idaho murder suspect on multiple grounds.

Kohberger, 29, is charged with four counts of murder and burglary after he allegedly killed Xana Kernodle, 20; Ethan Chapin, 20; Kaylee Goncalves, 21; and Madison Mogen, 21, on Nov. 13, 2022.

Among Kohberger’s defense attorneys’ arguments against the death penalty are their claims that “Idaho has no viable method for killing” in a capital punishment case, the state’s method for obtaining a death penalty punishment is “unconstitutional,” a capital murder case cannot be prepared in 10 months, and the death penalty violates the “prohibition against cruel and unusual punishment.”

Executing Kohberger “by means of lethal injection or a gunshot as conceived of by the Idaho Department of Corrections (IDOC) would violate his right to be free from cruel and unusual punishment under the Eighth Amendment and his right to due process under the Fourteenth Amendment of the United States Constitution,” his attorneys wrote.

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They also argue that death by firing squad, which is the second legal execution method in Idaho after lethal injection, “is not and was never constitutional.”

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In other documents filed Thursday, Kohberger’s defense states that “punishment which does not comport with the evolving standards of a modern, civilized society is cruel and unusual.”

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“The vast majority of modern, civilized society has already abolished capital punishment because the execution of human beings by governments is recognized to be a violation of the dignity and spirit of human beings,” his attorneys wrote. “The institutional killing of civilian prisoners affronts the modern, civilized world. The United States has been routinely condemned by the international community for continuing to execute its own people.”

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Meanwhile, prosecutors have argued that the state is trying to enforce Idaho law that says “a jury is entitled to decide not only guilt but potential penalty.”

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“We are simply trying to fulfill our responsibilities under the law. To characterize it as the State is trying, is wanting, is trying to kill someone, is just simply appealing to raw emotion, and it has no place in this courtroom,” prosecutors previously stated.

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The defendant — a 29-year-old former criminology Ph.D. student at Washington State University in nearby Pullman, Washington — is accused of stabbing the four University of Idaho students with a KA-BAR-style knife in their home near campus in the early morning hours of Nov. 13, 2022, a Sunday. 

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Kohberger was arrested in late December 2022 at his family’s home in Pennsylvania. 

His trial is scheduled to take place no later than the summer of 2025.