Scientists in California have cracked the code for measuring THC impairment.
Translation: Officers could soon have access to marijuana breathalyzers.
Before now, law enforcement could only measure whether THC was in a person's system. (Video via Fusion)
But the chemical can stay in the body for a long time. That makes existing tests impractical for traffic stops. (Video via CBC)
Next step for the weed breathalyzer: "optimizing the technology for a handheld device."
Soon after: Clinical trials will begin in California.
This video includes images by Getty Images.