Durden v. State

Birdsong, Chief Judge.

This is an appeal of a conviction for two counts of driving under the influence in violation of OCGA § 40-6-391. The main ground of appeal involves expert testimony as to appellant’s blood and urine samples and the evidence of marijuana usage shown thereby. Held:

1. The trial court erred in admitting evidence of, and allowing the forensic expert to testify to, the presence of 180 to 200 nanograms of THC metabolites per milliliter of blood and urine sampled, and as to the degree, quantity, and effect of marijuana usage indicated or proved by these particular test results.

Th…