Part 2: Weakness in Cannabis Testing and Legal Implications

While these tests are designed to identify impairment, they have significant weaknesses. In this section, we analyze 

the flaws in these methods and their potential to introduce bias.

Flaws in Field Sobriety Tests:

- Lack of Specificity: Cannabis impairment manifests differently from alcohol.

- Non-Scientific Basis: Tests are not validated for cannabis.

- Subjectivity: Results rely on officer interpretation, introducing bias.

Limitations of Saliva Swabs:

- Detection Windows: THC remains detectable long after impairment has worn off.

- Accuracy Issues: Swabs detect recent use but not impairment.

Blood Tests:

- Frequent users may have THC in their blood without being impaired.

- THC can remain in the bloodstream for days.

Bias in DRE Evaluations:

- Evaluations are subjective, increasing the risk of unfair outcomes.

Legal Implications:

- State v. Gerhardt (2017): Massachusetts Supreme Court ruled field sobriety tests are not valid for cannabis.

- People v. McKinnon (2021): California court ruled THC presence alone does not prove impairment.