When an individual is stopped for a DUI, law enforcement will initially look for physical characteristics showing that a person may have consumed alcohol or illegal substances. That would be odors of alcohol, blood shot eyes, problems with balance, odors of other drugs. They’re also going to look for cognitive impairment, and that is whether or not a person is acting appropriately, responding with the appropriate level of respect to law enforcement, whether or not their physical skills are diminished in providing paperwork. Law enforcement has been trained to look for those clues and repetitively will always be looking for those clues initially upon a traffic stop.