Circumstantial evidence is evidence that prosecutors will use to prove that a driver was in fact driving his vehicle prior to being found behind the wheel of the car.  These situations pose the question: can a driver be found guilty of DUI when the vehicle's engine was not running and the ignition was in the park position? The answer is a simple "Yes."  It requires the prosecution to lay the groundwork that the driver operated the vehicle at some point prior to the stop and that said driver was under the influnce while driving.  Circumstantial evidence can be strong:  the accused is found in the driver's seat, with the keys in or around him; and the hood of the vehicle is warm to the touch.  This would indicate the vehicle had recently been driven or the engine had been running prior to the contact between law enforcement and the driver.  In this scenario, driver's rarely have a good explanation.  While one can assert that someone else drove them there, it is rare that a 3rd party is found and who steps up and admits to driving.  The driver is usually stuck. In this instance, it is best to say nothing.  As an accused driver, you have the right to remain silent.  The more you speak, the more evidence of impairment you are providing, such as slurred speech,  repeating of questions to the officer, contradicting prior statements, etc.  When in doubt, you simply state you "want to speak to your lawyer" first and then allow the officers to conduct their DUI investigation without your help.  Assuming you get arrested and charged with DUI, you at least do not have to defend any incriminating statements you made.  The idea of taking or refusing field sobriety testing will be addressed in a separate post. Regardless of how you handle yourself when confronted by law enforcement, remember that circumstantial evidence can and will be used against you to make a case for impaired driving.