The prosecutor in the Karen Read murder trial focused on Read's blood alcohol level the night John O'Keefe died.
www.cbsnews.com
BAC .093 when her boood was drawn. They used BAC retrograde extraction to ‘guesstimate’ her BAC to be minimum 0.135% or a maximum of 0.292%.
Reverse extrapolation of a person’s BAC to the time they were driving relies on lots of assumptions, including that the person was eliminating alcohol at a standard rate of 0.015% per hour. That rate is based on average values for thing like age, sex, liver and kidney function, hydration, metabolism, body fat, and more, but there are factors that can vary widely from person to person. It also assumes the BAC was already declining, which may not have been the case.
MOO