09/25/2026
A later blood or breath test does not directly show what a driver’s alcohol concentration was when they were behind the wheel. Prosecutors may use retrograde extrapolation to work backward from that later result, but the estimate depends on assumptions about timing, absorption, drinking history, food, and other facts. If retrograde extrapolation is being used in your Texas DWI case, contact Amanda Webb - DWI Lawyer. We can examine the testing timeline and the assumptions behind the State’s calculation. https://bit.ly/4yV2rrv