Post-Conviction DNA Analysis

DNA technology, forensic science, and testing procedures have advanced over the years. As you might expect, the use of DNA evidence in the criminal justice system has, too. DNA evidence is a powerful tool for both the state and defendants in a criminal case.

Prosecutors and defense attorneys routinely use DNA evidence at trial to prove whether a defendant committed a crime. Parties may also use DNA analysis after a conviction. Requests for post-conviction DNA testing are so prevalent that the federal government and every state have passed laws governing when and how a convict can request DNA testing after a conviction.

The following is an overview of DNA analysis used to obtain post-conviction relief. First, it briefly describes DNA evidence. Then, it discusses post-conviction DNA testing and how parties use it to exonerate convicted people. It concludes with Supreme Court precedent addressing DNA analysis and legal relief for the exonerated.

What Is DNA Evidence?

In 1985, British scientist Alec Jeffreys developed DNA (deoxyribonucleic acid) testing. DNA evidence comes from biological material, such as hair and blood. Investigators often collect this type of physical evidence from crime scenes.

Every person has a unique DNA profile. So, biological evidence from a crime scene may raise a reasonable probability that a specific person was at the scene. Each state has laws governing DNA collection and testing procedures. For more information, check your state's DNA testing statutes.

The Federal Bureau of Investigations (FBI) and most police departments keep DNA databases. For example, the Combined DNA Index System (CODIS) compiles genetic evidence. If crime scene evidence includes DNA samples, the agency may log it in CODIS. This allows law enforcement agencies to cross-reference DNA test results with logged DNA samples quickly.

DNA Analysis After a Conviction: The Basics

The use of post-conviction DNA analysis has resulted in the release of many innocent people. The Innocence Project uses post-conviction DNA analysis to free the wrongfully convicted. Its use of post-conviction DNA analysis has resulted in 202 exonerations and releases of prisoners. According to the University of Michigan Law School, post-conviction DNA analysis led to 594 exonerations between 1989 and 2023.

Post-conviction DNA analysis is typically available in two types of cases:

  • Testing wasn't available at the time of the original trial
  • Technological advances offer a more probative test than the one used previously
  • This analysis may result in the release of a convicted prisoner in two ways:
  • DNA evidence proves the prisoner didn't commit the crime in question
  • DNA evidence justifies overturning the conviction without conclusively proving innocence

DNA evidence is very accurate. But post-conviction testing is only as accurate as the DNA testing procedure. Sometimes, someone may unknowingly contaminate a DNA sample in the chain of custody. If someone believes the DNA evidence was compromised, they may challenge its use.

Categories of Post-Conviction DNA Analysis Cases

According to the National Institute of Justice's DNA Initiative, post-conviction DNA cases fall into five broad categories, including cases where:

  1. The prosecution and the defense agree to a post-conviction DNA analysis. In this category, the two sides may work together without judicial intervention.
  2. Testing may not prove innocence on its own, but it could help secure a new trial, a pardon, a commutation, or executive clemency. This category also includes cases where the parties can't agree on how helpful the testing may be. They will likely require a judicial officer's assistance to resolve their differences.
  3. Testing will not produce conclusive results.
  4. Testing cannot proceed because of lost, damaged, or destroyed biological samples. This category also includes instances where investigators did not collect biological samples.
  5. The prisoner makes a false claim of innocence, and the prosecutor and defense counsel agree not to test.

Cases that fall into the second category require judges to examine the case's details. They must then determine whether the situation meets the requirements of the applicable statute. DNA testing may proceed if the court finds the facts to meet the requirements.

Standards for Post-Conviction DNA Analysis Cases

State laws set out the standard for DNA analysis requests after conviction. The federal government also has a statute covering inmate DNA testing: 18 U.S.C. Section 3600. Judges use the standards in these laws to determine whether the evidence will have enough impact to justify reopening the case.

The specific standard that an applicant must meet varies from state to state. In general, most states require conclusive proof that the new DNA evidence would have altered the result of the first trial. The exact standard may differ among jurisdictions.

Applicants must typically meet other requirements as well. Most often, there is a time limit on how soon they must apply after discovering new evidence. State law determines the time limits within which they must apply.

The Supreme Court and Post-Conviction DNA Analysis

The United States Supreme Court first addressed the issue of post-conviction DNA analysis in the case District Attorney's Office v. Osborne. In that case, William Osborne, a man convicted of rape and attempted murder, claimed a constitutional right to subject DNA samples collected in the case to newer, more accurate DNA analysis. He claimed the new evidence would help him to prove his innocence.

The Court denied Osborne the opportunity to test the DNA samples. A divided Court ruled, among other things, that there is no constitutional right to post-conviction DNA analysis. The Court determined that recognizing a constitutional right would undermine the state laws already in effect.

Compensation for the Wrongfully Convicted

The federal government provides compensation of up to $50,000.00 to exonerated inmates. Most states (35) and the District of Columbia have laws that compensate wrongfully convicted inmates. The exoneree must show by a preponderance of the evidence that they did not commit the alleged crime to receive compensation.

Get Help With Your Exoneration Efforts: Contact an Attorney

DNA evidence can potentially exonerate you or raise reasonable doubt in your case. But if your case involves DNA evidence, you need an attorney with experience handling these kinds of cases. Whether making an appeal or facing trial, you can speak with an expert criminal defense attorney in your area today. An experienced attorney can provide legal advice regarding the following:

  • General information about criminal lawguilty pleas, and the federal court system
  • Specific information for your criminal case, including capital cases and sexual assault charges
  • The process an indigent criminal defendant may use to request post-conviction DNA testing

Contact a criminal defense attorney today if new evidence arises in your criminal case.

Was this helpful?

Can I Solve This on My Own or Do I Need an Attorney?

  • Complex criminal defense situations usually require a lawyer
  • Defense attorneys can help protect your rights
  • A lawyer can seek to reduce or eliminate criminal penalties

Get tailored advice and ask your legal questions. Many attorneys offer free consultations.


If you need an attorney, find one right now.