EVIDENCE LIBRARY
Toxicology Laboratory Records: Evidence Review Checklist
A checklist of toxicology laboratory records for evidence review, covering specimen handling, methods, validation, quality controls, and underlying data.
A final toxicology report is important, but it is often only one part of the record needed to understand how a conclusion was reached. The appropriate request depends on the issue in dispute, the method used, the specimen, and the laboratory’s available documentation.
Core records
- Final toxicology report and any amended or supplemental report
- Specimen collection, accession, handling, and chain-of-custody documentation
- Method identification, analyte scope, LOD, LOQ, and reporting limits, and relevant validation materials
- Calibration, control, and quality-assurance records associated with the batch when available
- Chromatograms, spectra, integration records, or other underlying analytical data when relevant to the method and dispute
Questions the record can help answer
- What exactly was tested, confirmed, and reported?
- Was the result qualitative or quantitative, and what method produced it?
- What specimen was used, and how was it collected and handled?
- What controls and reporting criteria were applicable to the result?
- Which conclusion is supported by the record, and which needs additional evidence?
Related evidence guides
- Screening versus confirmation
- Limits of a negative urine immunoassay
- Postmortem blood sampling and specimen selection
- Breath-test records for scientific review
Minimum record set by disputed issue
The most useful production is issue-driven rather than simply voluminous. A result-identification dispute usually calls for method scope, identification criteria, chromatograms or spectra, and review records. A quantitative dispute adds calibration, control results, integration history, dilution records, and the laboratory’s measurement-uncertainty framework. A specimen-integrity dispute places greater weight on collection, seal history, accessioning, storage, preservation, transfers, and chain of custody.
| Question | Records with highest review value |
|---|---|
| Was the analyte correctly identified? | Method, identification criteria, calibrators/controls, chromatograms or spectra, analyst and technical-review records |
| Is the reported concentration supportable? | Calibration model, calibration points, QC results, integration records, dilution history, calculation records, uncertainty information |
| Was the specimen suitable and traceable? | Collection record, container/preservative information, accession record, seals, transfer history, storage conditions, aliquot history |
| Could a negative result reflect test scope? | Analyte list, screening cutoff, confirmation scope, LOD/LOQ or reporting limit, method version, specimen matrix |
| Was an amended report scientifically explained? | All report versions, amendment reason, audit trail, reanalysis records, calculations, authorizations, correspondence |
How to read the packet in sequence
- Anchor the specimen. Confirm identity, matrix, collection time, collection site, preservative, seal status, and storage history. See specimen collection, storage and stability, and chain of custody.
- Define the method’s intended use. Determine whether the procedure was a screen, confirmation, identification method, or quantitative assay and whether it was validated for the analyte and matrix at issue. See method validation.
- Review calibration and controls before the case result. A reported number should be interpreted with its calibration model, quality-control results, blanks, carryover checks, and acceptance criteria. See calibration and quality control.
- Then review the underlying signal. For chromatographic or mass-spectrometric methods, evaluate retention behavior, identification transitions or ions, signal quality, integration, interferences, and any manual edits. See chromatography and mass spectrometry.
- Separate measurement from interpretation. After determining what the laboratory reliably measured, address timing, dose, impairment, toxicity, or causation as separate inferential questions.
Standards are a starting point, not a substitute for the case file
ANSI/ASB Standard 036 sets minimum practices for validating targeted forensic toxicology methods and states that validation is performed to demonstrate that a method is fit for its intended use. The NIST OSAC Registry separately identifies published and proposed forensic-science standards that have undergone technical and quality review. Those materials can help frame a records review, but the laboratory’s own current method, validation package, SOPs, quality records, and case data remain essential to a case-specific assessment.
- ANSI/ASB Standard 036: Standard Practices for Method Validation in Forensic Toxicology
- NIST OSAC Registry of forensic science standards
Do not collapse the analysis
A laboratory finding can be reliable for its stated analytical purpose while still being limited in what it establishes about timing, dose, impairment, causation, or a disputed event. The evidence question should be framed before any conclusion is drawn.
Educational information only. This guide is not legal advice and does not prescribe a universal discovery request. Required records vary by jurisdiction, laboratory, and scientific issue.