Officer Kevin McWilliams stopped their car for various violations as the couple headed north on the highway toward their home in Monroe, NY, around 1:30 a.m., Detective Lt. Edward Kane said.
Williams immediately spotted a needle and empty heroin bag on the center console, Kane said.
Both the driver, Erik Shepard, 27, and his fiancée, Jacqueline Completo, 20, were apparently under the influence of heroin, he said.
Shepard also turned out to be wanted for DWI in Pennsylvania, the lieutenant said.
Completo -- who is five months pregnant -- was released to a family member after being processed on drug charges.
Shepard, who also was charged with drug offenses, was sent to the Bergen County Jail to await extradition to Pennsylvania.
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