The Trouble with Criminal Toxicology Testing for Marijuana

Recently, TW Forensic Consulting had the privilege to assist an attorney representing a young man who was facing jail time for a car accident that had resulted in injuries to the occupants. The District Attorney filed an indictment, which stated that the accused was responsible for these injuries because he drove while allegedly intoxicated, as evidenced by the toxicology report showing a positive result for THC.

The technical name for THC is tetrahydrocannabinol and is the main psychoactive ingredient in marijuana. The accused admitted to occasionally smoking marijuana, but he denied using in the last few days leading up to the accident.

Using evidence-based research articles, TW Forensic Consulting wrote a report including a section titled “Lab Results and Interpretation”. A research study titled “Do Tetrahydrocannabinol Concentrations Indicate Recent Use in Chronic Cannabis Users?” was published in a peer-reviewed journal and cited in this section. It studied a large population of individuals who used marijuana, with the frequency varying from rarely to daily. The study showed testing the blood (and urine) for THC seven days after the last use resulted in THC still being present in the blood.

It is the information provided in this report that convinced the DA to drop the charges against the eighteen-year-old man. Another successful case thanks to the research and written report of TW Forensic Consulting.

Written by Tristan Ashly Wristen, RN, BSN, MSN, FN-CSA, LNC