Junk Science and Capital Punishment

Junk Science and Capital Punishment

For defendants facing the death penalty, the admission of unreliable and unfair “junk science” testimony is often deadly. Junk science is presented in many forms, including wrongful testimony from “future dangerousness” experts, often based on race or other traits that have nothing to do with a defendant’s likeliness to cause future harm, or unreliable testimony from experts in medical or science fields about the significance of certain crime evidence.

Juries are often more likely to credit such "expert" testimony precisely because it comes from professionals whom juries are far more likely to trust.

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End the Death Penalty in Your State (Map)

The state of Georgia has executed Troy Davis, despite serious concerns that he was wrongly convicted in 1989 of killing a police officer. This case makes clear that the death penalty system in the United States is broken beyond repair. It is arbitrary, discriminatory and comes at an enormous cost to taxpayers, and it must be ended.


The Case Against the Death Penalty (2011 Resource)

The American Civil Liberties Union believes the death penalty inherently violates the constitutional ban against cruel and unusual punishment and the guarantees of due process of law and of equal protection under the law. Furthermore, we hold that the state should not arrogate unto itself the right to kill human beings – especially when it kills with premeditation and ceremony, in the name of the law or in the name of its people, or when it does so in an arbitrary and discriminatory fashion.

Faces of Justice Denied - Cameron Todd Willingham and Claude Jones (2010 Resource)

Twelve people have been exonerated from Texas’ death row and yet the state of Texas has made few if any attempts to reform its death penalty system. Even more troubling, recent developments strongly suggest that Texas has allowed the execution of two men who were almost certainly innocent and whose convictions were largely based on unreliable scientific evidence.


Galloway v. Mississippi

The ACLU is appealing the conviction and death sentence of Mississippi death row inmate Leslie Galloway, who was sentenced to death in 2010 for the murder of Shakeylia Anderson. Galloway was eligible for a capital trial based solely on the scientifically invalid testimony of forensic pathologist Dr. Paul McGarry that the victim had been also subjected to sexual battery. In the appeal, the ACLU challenges Dr. McGarry’s bogus testimony as well as numerous other errors at the trial that violated Galloway’s constitutional rights.

Coble v. Texas

The ACLU filed a petition for certiorari in the U.S. Supreme Court on behalf of Billie Wayne Coble, a Texas death row inmate. Mr. Coble was sentenced to die in large part because of the testimony of Dr. Richard Coons, who testified that Mr. Coble was likely to pose a "future danger," a required finding in Texas before the jury can impose death. Dr. Coon's testimony was based on his own, idiosyncratic, subjective methodology, and he was unable to cite to a single book, treatise or article discussing any of the factors he identified as important in his methodology. The Texas Court of Criminal Appeals (CCA) found that the testimony of an "expert" on future dangerousness violated the rules of evidence because it was so utterly unreliable.

Estrada v. Texas

Adrian Estrada’s death sentence was thrown out last June after the Texas Court of Criminal Appeals found that A.P. Merillat, who investigates prison crimes for Texas, gave wrongful testimony that led the jury to find that Estrada posed a future threat to society.

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