Many times, the police may find that someone stopped for DUI has no alcohol on board. That doesn't mean the case will get dropped. It just means that the police will suspect drugs instead of alcohol. Here are some articles about what the Florida law says about driving while under the influence of drugs.
Board Certification as a DUI Specialist by the National College for DUI Defense. Formal NHTSA Certification as an Instructor of the Standardized Field Sobriety Tests given by police in DUI cases. Formal training as a NHTSA Drug Recognition Evaluator. ("Drug Evaluation & Classification") Formal training to operate the Intoxilyzer 8000, Florida's official breath test instrument. Extensive experience in teaching other attorneys how to handle DUI cases. Hundreds of jury trials both as defense lawyer and as prosecutor.