There are some common law defenses available in DWI cases in New Jersey. Although the defenses generally available under the New Jersey Code of Criminal Justice are not available to a defendant in a drunk driving case (because it is a strict liability offense and a per se violation of the statute), common law defenses may be asserted. For example, the defense of duress under New Jersey common law may be used as a defense in a drunk driving case. State v. Fogarty, 128 N.J. 59 (1992). The easiest way to understand the defense of duress is someone is holding a gun to your head and forces you to drive even though you are intoxicated. This would be a valid common law defense of duress to a charge of drinking and driving in New Jersey.

Double jeapardy also applies in certain circumstances in New Jersey DWI cases. A plea of guilty in municipal court to drunk driving, which included merged offenses of reckless driving and failure to keep right, prevented a subsequent Superior Court prosecution for death by auto arising from the same incident based upon the double jeapardy clauses of the State and Federal Constitutions. State v. Dively, 92 N.J. 573 (1983).