Unvalidated or Improper Forensic Science

Unvalidated or Improper Forensic Science

Unvalidated or improper forensic science is a leading cause of wrongful conviction in the United States.

Many techniques still in use today -- such as hair microscopy, bite mark comparisons, firearm testing or tool mark analysis – have never been subjected to rigorous scientific evaluation. Other methods – such as serology (commonly known as blood typing) – have been properly validated but are sometimes improperly conducted or inaccurately conveyed in trial testimony. In some cases, forensic analysts have fabricated results or engaged in other misconduct.

In approximately 50% of DNA exonerations, unvalidated or improper forensic science contributed to the wrongful conviction. But, while DNA exonerations are a window into the effect of unvalidated or improper forensic science contributing to wrongful convictions, DNA does not solve the problem. Experts estimate that only 5-10% of all criminal cases involve biological evidence that could be subjected to DNA testing. In the other 90-95% of crimes, DNA testing is not an option – so the criminal justice system relies on other kinds of evidence, including forensic disciplines that may not be scientifically sound or properly conducted.

The Absence of Scientific Standards

As outlined in the National Academy of Sciences report, Strengthening Forensic Science in the United States: A Path Forward, many forensic disciplines have evolved primarily through their use in individual cases and have not been scientifically validated or standardized.

As a result, forensic analysts sometimes testify in cases without a proper scientific basis for their findings. Testimony about more dubious forensic disciplines, such as efforts to match a defendant’s teeth to marks on a victim or attempts to compare a defendant’s voice to a voicemail recording, are cloaked in science but lack even the most basic scientific standards. Even within forensic disciplines that are more firmly grounded in science, evidence is often made to sound more precise than it should. For example, analysts will testify that hairs from a crime scene “match” or “are consistent with” defendants’ hair – but because scientific research on validity and reliability of hair analysis is lacking, they have no way of knowing how rare these similarities are, so there is no way to know how meaningful this evidence is.

Forensic Misconduct

The vast majority of forensic employees are hardworking, ethical and responsible. They use the best scientific techniques available to deliver objective, solid information – regardless of whether the science favors the defendant, supports the prosecution or is inconclusive.

In many cases, the science – rather than the scientist – is inadequate. In other cases, forensic analysts make mistakes that could result from lack of training, poor support or insufficient resources to meet an ever-growing demand. But in some cases, forensic analysts have engaged in misconduct. While these “bad apples” don’t reflect the entire forensic field, one fraudulent forensic analyst can taint countless cases. For example, in some wrongful convictions later overturned with DNA testing, forensic analysts fabricated test results, reported results when no tests were conducted or concealed parts of test results that were favorable to defendants. In virtually all of these cases, analysts had engaged in misconduct that led to multiple separate wrongful convictions, sometimes in multiple states.

A Plan for Reform

Unvalidated and improper forensic science continues to play a role in convictions across the country, and the National Academy of Sciences report calls strongly for reform to help identify perpetrators of crimes and protect the innocent from wrongful convictions.

The Just Science Coalition: Working Together for Forensic Science Reform

The Just Science Coalition is an emerging network that will include individuals and organizations working for reform of the forensic sciences. Our mission is to advocate for the governmental framework and resources necessary to ensure that forensic sciences in the United States are valid and reliable, and that their use in the criminal justice system promotes accurate justice: the identification of the guilty, the protection of the innocent, and safety and justice for victims and communities.

The coalition was formed in 2009 in the wake of a groundbreaking National Academy of Sciences report finding serious deficiencies in the nation's forensic science system and calling for major reforms and new research. The coalition seeks the establishment of an Office of Forensic Science Improvement and Support, consistent with that recommended by the NAS, to improve the accuracy of criminal investigations, support science-based prosecutions, and increase public safety.

In 2009, the coalition launched the Campaign for National Forensic Science Standards, an educational effort helping to build awareness and support for forensic reform across the nation and advocating with policymakers to make reform happen. The Campaign includes a national outreach network with representatives in 27 states and a group of university professors committed to establishing national standards for the use of forensic sciences in criminal prosecutions.

Learn more:

Campaign for National Forensic Science Standards
University Professors for National Forensic Science Standards
Just Science Coalition FAQs

If you or your organization would like to join the coalition or learn more about coalition efforts, contact Sarah Chu (schu@innocenceproject.org) at the Innocence Project.

To sign the petition urging Congress to create a federal science-based forensic entity, click here.