Hannah Knowles

“The results are recorded as an alcohol result with a value of 93 mg per deciliter.”

The hospital serum ethanol reading that forms the basis for all subsequent BAC calculations.

“So the 93 mg per deciliter serum ethanol concentration would convert to between 0.078 and 0.082%, or grams percent.”

The converted whole blood alcohol concentration at the time of the hospital blood draw (9:08 a.m.).

“And so we usually subtract 2 hours from the time interval when we're doing that minimum calculation to have a more conservative estimate.”

Explains that subtracting two hours produces a more conservative minimum estimate when the drinking history or time alcohol consumption stopped may be uncertain.

“That based on the 93 milligrams per deciliter value that was obtained at Good Samaritan, that the blood alcohol concentration for that individual at 12:45 a.m. could be between 0.14 and 0.28%.”

Knowles's retrograde extrapolation estimate that, based on the 93 mg/dL Good Samaritan value, the individual's blood alcohol concentration at 12:45 a.m. could have been between 0.14 and 0.28%.

“But as you're mentioning, the testing was not performed in my laboratory. I don't have any direct knowledge or understanding of their QC procedures, of their accreditation requirements, or their testing procedures at all.”

Establishes a complete gap between the accredited forensic standards Knowles upholds and the unknown standards of the hospital lab that produced the source data.

“The reliability of the results that my calculations were based on — my calculations are only as good as the numbers that I was provided. And like I said, the same math that I did here, I would do to my own internal standard or my own internal testing, anything that I performed testing on in the lab myself. But the results that I started from, I don't have any direct knowledge on their accuracy or reliability.”

The prosecution's own toxicology expert concedes she cannot vouch for the reliability of the blood test that underpins her entire BAC calculation.

“Correct. I have no direct knowledge of the accuracy or reliability. My calculations are solely based on the results of the Good Samaritan lab.”

Knowles says she relied on the reported Good Samaritan result while lacking direct knowledge of that laboratory's accuracy or reliability; the testimony does not itself establish that the reported result was erroneous.

“It certainly is. .28 is double .14.”

The prosecution's own expert concedes the extraordinary width of the BAC range, undermining the precision of the calculation.

“The foundation of my calculations would be incorrect. I would need to perform different calculations or factor in the information as it would become available and issue a different report.”

Knowles says that, under the hypothetical of alcohol consumption after 12:45 a.m., the foundation of her calculations would be incorrect and she would need different calculations or a revised report; she did not characterize the existing analysis as simply collapsing.

“The conversion factors come from published studies involving individuals that consumed alcohol, had samples collected from them, and their whole blood and their serum alcohol concentrations were compared.”

Reinforces the scientific basis of the conversion factors challenged on cross.

“Less than 5%. The vast majority of alcohol is eliminated from the body by an enzyme that breaks it down from alcohol into carbon dioxide and water.”

Minimizes the defense's line of questioning about bladder elimination affecting BAC calculations.

“That range is intentionally wide to ensure that the actual blood alcohol concentration lies somewhere between it. It's intending to account for a lot of the factors that we've been discussing.”

Reframes the wide 0.14–0.28% range as conservative methodology rather than unreliable science.