John J. Godfrey holds a Master of Science degree in Chemistry from the University of Maine. His background as an expert witness comes from not only his degree, but also from his many years of experience in the field. John (Jay) is an effective and knowledgeable witness in the areas of:

Gas Chromatography:
Jay has been using gas chromatography to analyze for ethanol (alcohol) in both blood and captured breath samples since 1994. He has been qualified as an expert in this area in both district and superior courts throughout the state of New Hampshire as well as courts in Georgia, Maine, Vermont and New York. He has never failed to be considered an expert by a court.

As an Evidentiary Breath Alcohol Technician, Jay uses his certification in order to make comparisons between the methods of analysis for breath alcohol via Infrared Spectroscopy versus Gas Chromatography.


When critiqueing the work from other labs, Jay uses his knowledge of and expertise gained by getting his lab, CG Labs, Inc, accredited by ASCLD/LAB (now ANAB) from 2013 to 2017.

Clients of CG Labs, LLC. appreciate the time spent on the phone with them in order to explain the chemistry behind the numbers on either this lab’s results or the results produced by the prosecution.

Pharmacokinetics of ethanol (alcohol):
Pharmacokinetics is the study of how a drug interacts with the human body. More simply stated, pharmacokinetics deals with the absorption and elimination of drugs, and in this case the drug is ethanol (alcohol). In 1998 Jay developed the “Kinetics Model” which simulates the passage of ethanol through the body and predicts ethanol concentrations as a function of time. The basis of this model comes from published research articles and it uses sophisticated mathematics. Where feasible, other widely accepted models are also used.

Jay has been qualified as an expert in the pharmacokinetics of ethanol in both district and superior courts in New Hampshire as well as by the Maine Bureau of Safety. His testimony is limited to just ethanol, not the interaction of other drugs, nor the pharmacodynamics of ethanol, (ie: how ethanol affects reaction times).

Pharmacokinetics is used to predict levels of Blood Alcohol Concentration (BAC) either backward or forward in time. Jay’s calculations and testimony are often times useful to the defense in order to show that the defendant was below the 0.08 g/100mL legal limit of intoxication at the time of operation even though he/she was over at the time of the chemical test.

As a workshop presenter:
Jay has been a presenter at many CLE’s regarding the analysis of ethanol via gas chromatography and the pharmacokinetics of ethanol. If you are interested in speaking to him about providing a presentation to your group please contact