Errors in toxicology testing and the need for full discovery

Abstract

Despite toxicology's foundation in analytical chemistry and quantitative measurements, it remains vulnerable to errors that can impact criminal justice outcomes. This paper presents a review of notable errors in toxicology collected over a combined 48 years of field experience. We highlight cases of toxicology errors from across multiple jurisdictions, categorizing them by type: traceability errors, calibration errors, discovery violations, maintenance failures, source code defects, fraud, errors due to interfering substances, reporting errors, laboratory contamination, and chain of custody breaches.

Our analysis reveals that many errors persisted for years before detection, with some lasting over a decade. Discovery often came from external sources rather than internal quality controls. Errors ranged from technical failures to deliberate misconduct, affecting thousands of cases. Notable patterns include institutional resistance to disclosure, retaliation against whistleblowers, and systematic withholding of exculpatory evidence. The compilation demonstrates vulnerabilities in toxicology. Key reforms needed include transparency through online discovery portals, mandatory retention of digital data, independent laboratory accreditation, whistleblower protections, and regular third-party audits. By examining past errors, the forensic science community can develop policies to prevent similar mistakes and enhance both scientific integrity and the pursuit of justice.