The Necessity of Machine Validation
A gas chromatograph must undergo rigorous validation before a laboratory can use it to report forensic blood results. Specifically, ANSI/ASB 036 establishes the minimum standards required to ensure a machine produces accurate data. In many cases, however, expert analysis reveals a significant lack of proper validation on these instruments.
The Conflict of Aqueous vs. Blood Solutions
A frequent issue in forensic testing is the failure to account for “matrix effects.” For example, labs often use aqueous (water-based) solutions for validation tests instead of actual blood. This approach is scientifically flawed, as it essentially compares apples to oranges rather than testing the substance in question.
Quality Control and ANSI/ASB 054 Standards
Standard ANSI/ASB 054 sets the minimum requirements for quality control, explicitly stating that labs must use matrix-matched controls. This means calibration requires blood-based solutions rather than aqueous ones. Despite this, many North Texas crime labs continue to calibrate with water-based solutions. Notably, an Austin Texas DPS study reported a discrepancy of approximately 20% when comparing these two methods.
Concerns Regarding Forensic Integrity
The reliability of agencies like the Texas DPS in safeguarding forensic integrity remains a major concern. For instance, laboratories have reported results from testing tubes that lacked the required preservative. Reporting such results is not forensically advisable and calls the entire testing process into question.
Judicial Oversight and Laboratory Accountability
Judges serve as the legal gatekeepers of forensic standards, and it is time for the courts to hold laboratories accountable. If judges allow labs to bypass established requirements without consequence, there is little incentive for these facilities to comply with the law.
Seeking Expert Investigation
Numerous issues within Texas DWI blood testing deserve a thorough investigation. With over 28 years of experience, Mimi Coffey understands exactly which forensic flaws to look for and how these technical failures directly impact the outcome of your case.
