Here are some important cases regarding proper DWI stops in New Jersey:

State v. Carpentieri, 82 N.J. 546 (1980)

The police must have an articulable and reasonable suspicion that a violation of the traffic laws has occurred in order to effectuate a stop for DWI. Basically, the New Jersey Supreme Court in this case applied the United States Supreme Court decision holding random traffic stops invalid but applied this rule only to those stops that occurred after the Supreme Court decision.

State v. Pegeese, 351 N.J.Super. 25 (App.Div.2002)

The police may not detain occupant for consent search absence violation or criminal conduct once evidence of proper licensing, registration and the like is supplied.

State v. Puzio, 379 N.J.Super. 378 (App.Div.2005)

A stop is invalid where it is based on a police officer’s mistaken understanding of the law. The court held that as an issue of first impression, officer’s belief that defendant was operating a vehicle in violation of statute requiring display of business and address on a commercial vehicle was not objectively reasonable, and thus officer was not justified in conducting investigatory stop of vehicle.

State v. Pitcher, 379 N.J.Super. 308 (App.Div.2005)

A stop based on an officer’s mistaken understanding of a fact, e.g., that the driver had a suspended license, will not be invalidated provided the officer’s actions were supported by a “reasonable” belief that the related facts were accurate. The court held that officer’s traffic stop, conducted in reliance on erroneous information in the DMV database that showed that the defendant had a suspended license, was reasonable.