“I’ve never seen this before,” California attorney Stacey Barrett tells the Guardian. “I’ve never even heard of it.” Barrett's client, 36-year-old Joseph Schwab, is facing a misdemeanor DUI charge—apparently over caffeine.

Schwab was pulled over in August 2015 in Solano County while driving home from his job installing glass, the Fairfield Daily Republic reports. An agent from the state department of alcoholic beverage control said Schwab cut her off and was driving erratically.

Barrett says a breathalyzer test at the scene showed a 0.00% alcohol level, but Schwab was booked into jail regardless. His blood was screened twice, testing negative for all sorts of drugs.

The only positive result: caffeine. A forensic toxicologist says he hasn't heard of anyone being charged with DUI for caffeine in his 41 years on the job, and Barrett calls the whole thing "absurd." Schwab's toxicology report didn't specify how much caffeine was in his system, and he says he's not sure he even consumed anything with caffeine that day.

The county's chief deputy DA says the DUI charge isn't based on caffeine but has offered no other evidence, Barrett says. It took the county nearly 10 months to bring charges against Schwab, who says the delay makes it harder for him to defend himself, such as by finding the crew he was working with that day to testify on his behalf.

With the trial finally about to start, Barrett is seeking to get the case dismissed. (This guy drank four or five energy drinks a day, then turned yellow.)

This article originally appeared on Newser: Man Charged With DUI Has Only Caffeine in System