Blood Evidence Authority Failure Through Selective Result Reporting at North Carolina State Bureau of Investigation

Blood evidence identification follows a two-stage analytical protocol. A presumptive screening test indicates whether a substance may be blood — these tests are sensitive but not specific, meaning they produce positive results for blood but also for certain other substances. A confirmatory test then determines whether the substance is definitively blood. Standard forensic practice and laboratory protocols require that both results be reported: the screening indication and the confirmatory determination. When the confirmatory test is negative or inconclusive, that result materially changes the evidentiary significance of the screening result.

The SBI Crime Laboratory was accredited and operated under standard operating procedures requiring documentation and reporting of test results. SBI analysts performed blood evidence examinations for law enforcement agencies across North Carolina, and their reports and testimony were presented in criminal trials as authoritative forensic evidence. The laboratory served a state criminal justice system processing thousands of cases annually, including capital cases.

In 2010, defense attorney obtained case files in the case of Greg Taylor, who had been convicted of murder in 1993 and imprisoned for seventeen years. Review of the SBI laboratory file revealed that the analyst had reported a positive presumptive test for blood on Taylor's vehicle — a result presented at trial as evidence linking him to the crime — while the file also contained a negative confirmatory test result that was not included in the report and was not disclosed to the defense. Taylor was exonerated by the North Carolina Innocence Inquiry Commission in February 2010.

The Taylor case prompted the state to commission an independent audit of SBI blood evidence reporting practices. The audit, led by former FBI supervisory agent Chris Swecker, reviewed over 15,000 case files spanning decades. The review identified more than 230 cases in which SBI analysts reported positive presumptive blood test results while omitting negative or inconclusive confirmatory results — including cases involving defendants who had been sentenced to death.

The reporting practice was invisible to the quality assurance system because the results that were reported were technically accurate — the screening test did indicate a positive result. The omission was not a fabricated result; it was a missing result. The case file documented the presumptive test and its positive finding. What the file did not document — or documented only in bench notes not included in the formal report — was the confirmatory test that contradicted the screening indication. A supervisory review checking whether the report accurately reflected documented test results would find no discrepancy, because the discrepancy existed between the report and a result the report did not include.

The practice was not limited to a single analyst. The audit identified the pattern across multiple analysts over a sixteen-year period, indicating an institutional norm rather than individual misconduct. The laboratory's culture treated the presumptive result as the reportable finding and the negative confirmatory as a non-result that did not require disclosure. This interpretation was not consistent with standard forensic practice, which requires disclosure of confirmatory results precisely because they qualify the evidentiary significance of the screening indication. But the quality assurance framework evaluated what was reported rather than evaluating whether everything that should have been reported was reported — a distinction between checking for accuracy and checking for completeness.

Greg Taylor was exonerated in 2010 after seventeen years of imprisonment. The Swecker audit's findings prompted legislative reform: North Carolina established an oversight commission for the SBI laboratory and mandated reporting protocols requiring disclosure of all test results, including negative and inconclusive confirmatory findings. Case reviews were initiated for the 230+ identified cases, though the process of locating defendants, evaluating the impact of the omitted results on individual cases, and providing legal relief proceeded over multiple years. The SBI implemented revised reporting procedures and additional supervisory requirements specifically addressing completeness of result disclosure.