DNA Testing and the Death Penalty

Document Date: October 3, 2011

In the U.S., as of September 2011, 273 people including 17 death row inmates, have been exonerated by use of DNA tests. The increasing use of DNA testing to help confirm the innocence or guilt in capital cases is one among many reforms that will help ensure that innocent people are not sentenced to death.

Deoxyribonucleic acid (DNA) is an essential molecule that is part of every cell in our body. Essential, because it enables an embryonic cell to become and exist as a functioning being.

DNA also has another important property: its uniqueness. While human and animal DNA’s are remarkably alike, modern science can reliably and with great accuracy distinguish between the DNA’s of individuals. Unique to an individual (except in the case of identical twins and bone marrow transplant recipients), unchanging throughout one’s life, and found in all one’s cells, DNA is a reliable identifier. DNA testing on biological samples such as skin, saliva, semen, blood or hair can help convict or exonerate with great accuracy. But only if the biological evidence is properly collected, preserved and kept from contamination. And only if the analysis is done correctly. Under those conditions DNA testing is the modern improved version of fingerprinting.

Earl Washington, Virginia
Convicted in 1984; Granted an absolute pardon in 2000

Mr. Washington suffers from pronounced mental retardation. In the course of police questioning he falsely confessed to the rape and murder of a woman in Culpeper, Virginia. A false confession is not unusual for mentally retarded persons, who often are eager to please and easily misled by authorities. Although he later recanted, Mr. Washington was sentenced to death in 1984. The victim had lived long enough to say that only one person was involved in the crime. DNA tests conducted long after Mr. Washington’s sentencing proved that he was not the rapist. Those test results, together with the victim’s statement cleared him. But he was not released. In October 2000, when additional DNA tests again excluded Mr. Washington as the perpetrator, Virginia Governor Jim Gilmore granted him an absolute pardon. By then Mr. Washington had served 16 years in prison, 14 of them on death row.

Frank Lee Smith, Florida
Convicted 1985; cleared (after death) in 2000

Mr. Smith was convicted of the rape and murder of a child. After the trial and sentencing the chief witness recanted her testimony. But Smith nevertheless was scheduled for execution. He died of cancer in January 2000, while on death row before the completion of the DNA test results that proved his innocence ten months later.

It’s important to know that DNA testing is a two-edged sword. No national data are available on the number of DNA test results that affirmed guilt, but of the cases subjected to DNA testing by the Innocence Project (a program of the Cardozo School of Law in New York) about half confirmed guilt.

Many instances of the use of DNA tests to rectify the horrible “mistakes” of our criminal justice system can be cited. In the sidebar are just two recent examples.

Although invaluable, DNA testing cannot always be put to use. In many cases, because of the nature of the crime, a DNA test cannot identify the murderer. In other cases DNA samples were not collected at the crime scene and preserved in a state suitable for testing today, or DNA testing of sufficient sophistication either was not available or not performed. And most significant, in some cases relevant samples may no longer be at hand because the evidence was destroyed.

Eyewitness misidentification is the single greatest cause of wrongful convictions nationwide, playing a role in more than 75% of convictions overturned through DNA testing. Go to for more information on the problem of eyewitness misidentification.

For many inmates the most important obstacle to DNA testing is the fact that in many jurisdictions officials refuse to enable inmates to have evidence tested using modern DNA testing methods, arguing that this would reopen too many old cases. Perhaps, though unstated, they fear that wrongful convictions would highlight the many “mistakes” of the criminal justice system and provide more fuel for the increasing calls for a pause in executions until we can be sure it is properly and fairly applied, and without the risk of executing the innocent.

A Gallup Poll, conducted in March 2000 found that 92% of Americans say those convicted before the technology was available should be given the opportunity to submit to DNA tests now – on the chance those tests might show their innocence. Thus this has become an important political issue.

As of 2011, 48 states have DNA access laws. All of the 34 death penalty states (Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Idaho, Indiana, Kansas, Kentucky, Louisiana, Maryland, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Washington and Wyoming) now give inmates, albeit to different extents, the right to DNA testing.

At the federal level, the Justice for All act, signed in 2004, is useful legislation in this struggle. The Justice For All Act includes the Innocence Protection Act, legislation that, among other things, grants any federal inmate the right to petition a federal court for DNA testing to support a claim of innocence. It also encourages states – through the power of the purse – to adopt adequate measures to preserve evidence and make postconviction DNA testing available in inmates seeking to prove their innocence.

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