This article is more than 6 years old

This article is more than 6 years old

Kerry Kennedy was acquitted on Friday of drugged driving, after she accidentally took a sleeping pill and then sideswiped a truck in a wild highway drive she said she didn’t remember.

Kennedy hugged and clasped hands with her lawyers after a six-person jury cleared her of driving while impaired, a misdemeanour that carried the potential for up to a year in jail, though that would be unlikely for a first-time offender.

“I’m incredibly grateful to the jury for working so hard on this case … and to my lawyers … and to my family and friends and so many other people who supported me,” Kennedy said. “I’m happy justice was done.”

A human-rights advocate, Kennedy is a scion of one political dynasty – a daughter of Senator Robert F Kennedy and niece of President John F Kennedy – and a onetime member of another, as the former wife of New York Governor Andrew Cuomo. Her 85-year-old mother, Ethel Kennedy, and other members of the famous family attended the trial, which drew so much attention that it was moved from a small-town courtroom to a bigger courthouse in White Plains.

Prosecutors and Kennedy’s lawyers agreed the 54-year-old took the sleeping drug zolpidem unintentionally, mistaking it for her daily thyroid medication, before heading off to her suburban New York gym on 13 July 2012. The trial centered on whether or not she realized she was impaired and should have stopped.

Despite the pill mix-up, Kennedy was “responsible for the chain of events that happened after that”, prosecutor Doreen Lloyd said in her summation. She argued that Kennedy shrugged off the symptoms because she was busy. Kennedy’s defence said what happened was an accident, not a crime.

“The DA never should have brought this case in the first place,” attorney William Aronwald said afterward. “Kerry Kennedy has the resources” to defend herself, he said. “What about the person who doesn’t?”

Kennedy said she didn’t remember anything that happened as she drove her Lexus on a New York interstate – swerving out of her lane, hitting a tractor-trailer, blowing a tire and continuing to the next exit, where she was found disoriented and slumped at the steering wheel, according to witnesses. Police said she failed several sobriety tests at the scene but passed several tests a few hours later at a police station.

“If I realised I was impaired, I would have pulled over,” Kennedy testified.

A few days later, Kennedy said her doctors believed her accident was caused by a seizure, stemming from a brain injury early in her life. Then blood tests found a small amount of zolpidem, sometimes sold under the brand name Ambien.

Kennedy’s defence introduced a medical journal article saying that people who take zolpidem frequently do not recognise their impairment; even the prosecution’s toxicology expert acknowledged the medication could lead to someone “sleep-driving” without knowing it. Kennedy’s lawyer, Gerald Lefcourt, said the drug “hijacks your ability to make decisions.

But the prosecutor said Kennedy’s testimony contradicted science showing the drug works gradually. And Lloyd spotlighted Kennedy’s shifting explanations of the episode, suggesting Kennedy was worried about her image.

Her family’s history crept into the trial when Lefcourt asked about her upbringing.

“My mother raised us because my father died when I was eight,” she said. “He was killed when he was running for president.”

But Lefcourt told jurors in his closing argument that Kennedy was “not seeking advantage because of her family”.

The trial, he noted, was “not a TV call-in program. This is an American court”.