In order to be convicted for a drunk driving offense in New Jersey, the state must demonstrate that a suspect has violated the statute. The burden of proof is on the prosecutor to prove both, that the suspect was intoxicated, and that they were operating a motor vehicle while they were intoxicated.

Often in trials concerning drunk driving charges, the issue is whether or not the prosecution has adequately shown intoxication. There are many potential errors or failures on the part of law enforcement that can return a false positive for intoxication. This may include miscalibrated testing equipment, inadequate training of the officers charged with administering the test, or some other problem with the testing procedure. The other half of the prosecution's burden does not always get as much notice, was the suspect actually operating the vehicle.

When a police officer pulls over a car that is driving down the road, it usually easier for the prosecution to demonstrate that the suspect was operating a vehicle. But arrests do not always arise from this scenario alone. In some cases the police never actually see the person driving the car, they are only able to infer that they have done so based on the circumstances.

It is not difficult to imagine a scenario when a person drives to a sporting event or campsite before consuming any alcohol, then has a few drinks, and gets into their car to turn on the radio or get something out of the glove compartment. If a police officer should happen upon the scene at that point they may assume that the driver had operated a motor vehicle while intoxicated when they in fact had not.

Source: Pearl River Patch, "N.J. Man Found Asleep At The Wheel In Pearl River Charged With DWI," Ryan Buncher, Feb 12, 2012