Authorities say prosecuting drivers under the influence of synthetic cannabinoid products, or spice, is proving to be a challenge in Georgia.
Changes in the drug are outpacing the crime lab's ability to test for it.
Richmond County sheriff's Sgt. Danny Whitehead says spice has an effect on drivers that's almost identical to marijuana.
The slowed reaction time and general lack of awareness make driving dangerous, but getting users off the street through court cases can be difficult because of a lack of proof.
Whitehead said that spice is a chemical drug that is constantly evolving. He said that every time one version becomes illegal, producers alter it slightly, making it legal again. The changes can make it difficult to test for the drug.