FAIRFIELD, Calif. - (KCRA/NBC) - A California man is facing a charge of driving under the influence, but the only drug found in his system was caffeine.
In August 2015, Joseph Schwab, 36, was driving home from work when an alcohol beverage control agent pulled him over.
The agent said Schwab was darting in-and-out of traffic, and she believed he was under the influence of a drug.
After a sobriety test, the agent found Schwab's pupils were dilated.
Schwab was taken to jail where he agreed to undergo a blood test. When the results were completed, the only drug that showed up was caffeine.
Experts say that caffeine is a drug, but it's not typically associated with impaired driving and might even help with driving.
Attorneys representing Schwab are stunned at the charge, but the district attorney says they plan to move forward with the case.
Officials believe Schwab was under the influence of a drug they don't screen for, but they know the case is going to be hard to prove.
Schwab says more than a year later the whole thing has hurt him financially and has hurt his reputation.
"This is a case without a blood result, right, so it makes it a very difficult challenge to prove in court to not have the blood result," said Solano County District Attorney Krishna Abrams.
"Looks like I'm undependable, and when you tell this type of story to somebody, they are naturally not going to believe you," said Schwab
Schwab and his attorney are filed a motion asking for the charges to be dismissed.
They say driving under the influence of caffeine is not a crime.