The Certificate Is the Beginning of the Review
A meaningful challenge does not rely on a general claim that blood testing is inaccurate. It identifies a specific legal, procedural, scientific, or interpretive weakness and connects that issue to admissibility or evidentiary weight.
A discrepancy matters most when it can be tied to the actual sample, analytical run, or legal element the State must prove.
Collection and Legal Authority
The defense may examine consent, warrant procedure, implied-consent issues, medical environment, collection protocol, tube selection, preservatives, seals, and documentation.
- Review warrant or consent records
- Confirm the collector, location, and collection protocol
- Examine kit expiration, seals, tubes, and preservatives
Laboratory Reliability
The analytical method should be supported by valid calibration, quality controls, blanks, maintenance, proficiency testing, and analyst documentation.
- Review the entire analytical batch
- Identify control, blank, or interference issues
- Compare reported values with the raw data
Interpretation and Timing
The concentration at the time of the draw is not automatically the concentration at the time of driving. Absorption, elimination, drinking pattern, and time intervals may matter.
- Build an accurate event timeline
- Avoid unsupported retrograde assumptions
- Consider medical, pharmacological, and physiological evidence

