Kerry Kennedy was found not guilty for driving under the influence on Friday in New York, NBCNews.com reported.
Kennedy, the daughter of the late Sen. Robert F. Kennedy, reportedly smiled as her verdict was handed down. Her mother, Ethel, hugged relatives in the court room.
Kennedy was arrested in 2012 after she crashed her SUV into a tractor-trailer. Toxicology reports showed she took a sleeping medication before she drove, prompting a DUI charge and resulting trial.
No one was injured in the crash.
She testified that she accidentally took the zolpidem pill instead of her daily thyroid medication before getting behind the wheel, and her lawyers argued that she did not realize she was impaired until after the crash.
"Mrs. Kennedy, let's get right to the heart of the issue," her lawyer asked on Wednesday. "Did you intentionally or knowingly take zolpidem?"
"No, I did not," she responded.
However, prosecutors claimed she knew she was not fit to drive and should have pulled over.
If she was convicted, she could have faced a year in prison.