A 2018 fatal car crash in Bogota, N.J., drew no media attention and resulted in no charges. The driver was the soon-to-be wife of Senator Robert Menendez, Report informs, citing foreign media outlets.

It was a cold evening in December 2018, and Nadine Arslanian, the soon-to-be wife of Senator Robert Menendez, was zipping through the darkened streets of suburban New Jersey in a black Mercedes-Benz sedan. She would later tell the police she did not see the man stepping out in front of her to cross a busy thoroughfare.

The crash that ensued just after 7:30 p.m. killed the man, Richard Koop, 49, almost instantly. His body was thrown to the curb just steps from his home and badly mangled, according to the Bergen County medical examiner.

After brief questioning, the police concluded that Ms. Menendez, who was alone in the vehicle, was “not at fault.” She was released without a summons.

What happened that night in the borough of Bogota outside New York City was not reported for years, leaving witnesses and Mr. Koop’s family to wonder if the fatal collision was deliberately kept quiet. But now, nearly five years later, the episode adds a startling dimension to a scandal that has shaken American politics, and raised new questions about the senator at its center.

The revelation helps fill in an important narrative gap around one of the most blatant bribes alleged in a 39-page federal indictment unveiled last month against Ms. Menendez, her powerful husband and three businessmen.

Prosecutors said in those charging papers that Ms. Menendez needed a car so badly after a December 2018 “accident” that the senator, a Democrat, was willing to try to suppress an unrelated criminal prosecution for a New Jersey businessman in exchange for a $60,000 Mercedes convertible. The fatal collision with Mr. Koop on Dec. 12 matches prosecutors’ terse description of the December 2018 crash.

Interviews, police reports, dashcam footage and other records reviewed by The New York Times also raise additional questions about the inquiry into the collision itself, which was reported earlier Wednesday by The Record of New Jersey. The questions include whether Mr. Menendez, a senator long accused of using the levers of government to help his friends, may have made an attempt to intervene.

There were reasons for suspicion at the time. One witness at the scene said in an interview that officers appeared to know who Ms. Menendez was and treated her with striking deference. Police recordings captured the voice of a man who identifies himself as a retired police officer from a nearby department. He can be heard saying he came to the scene as “a favor” to a friend whose wife knew Ms. Menendez.

The police reports indicate she was never tested for drugs or alcohol, and was allowed to leave the scene, not long before Mr. Koop was declared dead at a nearby hospital. Three days later, police investigators were sent to local bars to get more information on where Mr. Koop ‌had been in the hours before his death.