In the realm of criminal justice, the wrongful conviction of innocent individuals stands as a profound miscarriage of justice, a grave error that can irrevocably alter lives and shatter trust in the legal system. As of November 2023, the National Registry of Exonerations has documented over 3,000 wrongful convictions in the United States alone. These cases serve as stark reminders of the imperative need to scrutinize and rectify the flaws within our criminal justice system.
The Role of Faulty Forensic Science
Dr. Jon Gould, a prominent figure in the field of criminal justice, has illuminated a troubling aspect contributing to wrongful convictions – faulty forensic science. As a pioneer in research assessing the impact of forensic science on wrongful convictions, Dr. Gould has identified several key factors associated with these injustices. These factors include flawed eyewitness identification, coerced confessions, unreliable testimonies, questionable police and prosecutorial conduct, inadequate defense representation, and, significantly, issues within forensic science.
It is crucial to distinguish that these factors are deemed “contributors” rather than outright “causes” of wrongful convictions. This distinction arises from the complex nature of criminal cases and the multitude of variables at play. Nonetheless, the role of forensic evidence in these cases cannot be underestimated.
Unpacking Forensic Errors
To gain a deeper understanding of the specific issues related to forensic evidence, the National Institute of Justice (NIJ) undertook a comprehensive analysis. Dr. John Morgan, an independent research consultant, was enlisted to examine and elucidate the impact of forensic science on cases categorized by the National Registry of Exonerations as involving “false or misleading forensic evidence.”
Dr. Morgan’s analysis delved into a dataset comprising 732 cases and 1,391 forensic examinations, encompassing a wide range of forensic disciplines, from serology and forensic pathology to DNA analysis and latent fingerprint examination.
Identifying Error Types
One of the notable outcomes of Dr. Morgan’s research was the development of a forensic error typology, which categorizes factors contributing to misstatements in forensic science reports, errors in individualization or classification, testimony errors, issues during trials, and problems related to evidence handling and reporting.
Here’s a closer look at these error types:
Type 1 – Forensic Science Reports
Errors in forensic science reports often arise from laboratory mistakes, poor communication, or resource constraints. These issues can undermine the credibility of forensic findings.
Type 2 – Individualization or Classification
This error type pertains to incorrect individualization or classification of evidence or misinterpreting forensic results. Such errors can have a profound impact on the outcome of a case.
Type 3 – Testimony
Errors in forensic testimony during trials can distort the perception of scientific evidence. These errors may be intentional or inadvertent but are equally detrimental to pursuing justice.
Type 4 – Officer of the Court
Errors committed by individuals within the legal system, such as excluding evidence or accepting faulty testimony, can contribute to wrongful convictions.
Type 5 – Evidence Handling and Reporting
Failure to collect, examine, or report potentially probative forensic evidence during a police investigation or at trial can have dire consequences. Issues like chain of custody, lost evidence, or police misconduct can erode the integrity of a case.
Disproportionate Impact
Dr. Morgan’s analysis uncovered that specific forensic disciplines exhibited a higher error propensity. Notably, seized drug analysis, bitemark comparison, shoe/foot impression analysis, and forensic medicine (pediatric sexual abuse) emerged as disciplines with a higher percentage of errors. These errors ranged from incorrect identifications to procedural lapses.
In detail:
- Seized Drug Analysis: This field showed a 100% rate of examinations containing at least one case error. Most of these errors occurred due to issues with drug testing kits in the field rather than in the laboratory.
- Bitemark Comparison: Bitemark examiners, often independent consultants, exhibited a 77% rate of examinations containing errors, contributing disproportionately to wrongful convictions.
- Shoe/Foot Impression Analysis: Errors occurred in 66% of examinations in this field, with 41% involving individualization or classification errors.
- Forensic Medicine (Pediatric Sexual Abuse): This discipline exhibited errors in 72% of examinations, with 34% involving individualization or classification errors.
Key Findings Across Forensic Disciplines
Dr. Morgan’s research yielded insights into specific disciplines and their associated errors:
Serology
Most errors were related to blood typing (serological typing) and characterized by testimony errors, best practice failures (such as failure to collect reference samples or conduct tests correctly), and inadequate defense.
Hair Comparison
Most testimony errors conformed to the standards recognized at the time of the trial but would not conform to current standards.
Latent Fingerprints
Almost all errors were associated with fraud or uncertified examiners who clearly violated basic standards.
Gunshot Residue
Testimony often did not clarify the limits of the analysis, such as the possibility of secondary transfer and uncertainties of interpretation.
DNA Evidence
Errors were often associated with identification and classification errors. Labs frequently used early DNA methods that lacked reliability in testing and interpretation, with DNA mixture samples being a common source of evidence interpretation error.
Bitemark Comparison
Cases involving bitemark comparisons were associated with a disproportionate share of incorrect identifications and wrongful convictions. Bitemark examiners were often independent consultants outside the structure of forensic science organizations, potentially lacking effective mechanisms for enforcing standards.
Seized Drug Analysis
Out of 130 errors, only one occurred in an actual forensic laboratory, while the remaining 129 were due to errors using drug testing kits in the field.
The Role of Cognitive Bias
Dr. Morgan also highlighted the presence of cognitive bias in some forensic disciplines. Certain fields, including bitemark comparison, fire debris investigation, forensic medicine, and forensic pathology, were more susceptible to cognitive bias. This underscores the need for scientists to consider contextual information and maintain objectivity in their analyses.
Striving for High-Reliability
In fields outside forensic science, high-reliability industries like air traffic control employ rigorous follow-up analyses to prevent errors. In contrast, forensic science has often lacked such quality control mechanisms.
Forensic science organizations should view wrongful convictions as sentinel events that expose systemic deficiencies within specific laboratories. Dr. Morgan emphasized that actors within the broader criminal justice system, such as investigators and prosecutors, can also contribute to errors by disregarding exculpatory forensic results due to their own biases.
A Path to Improvement
Dr. Morgan’s typology of forensic errors serves as a valuable resource for the forensic science community. It facilitates further research and helps pinpoint areas within forensic science that require improvement. Some of the key areas highlighted by Dr. Morgan’s work include:
- The need for validated scientific standards and adherence to best practices.
- Simplification of forensic analysis processes to reduce complexity.
- Confirmation of presumptive tests by forensic laboratories.
- Greater oversight of independent experts in forensic analysis.
- Safeguarding against the suppression or misrepresentation of forensic evidence.
In conclusion, addressing the impact of false or misleading forensic evidence on wrongful convictions is paramount to bolstering trust in our criminal justice system. The development and strict enforcement of clear standards within each forensic science discipline, coupled with robust governance structures, are essential steps toward minimizing wrongful convictions and ensuring justice prevails.
About This Article
National Institute of Justice, “The Impact of False or Misleading Forensic Evidence on Wrongful Convictions,” November 28, 2023, nij.ojp.gov:
https://nij.ojp.gov/topics/articles/impact-false-or-misleading-forensic-evidence-wrongful-convictions
