New York ( CNN ) -- Investigators found a sleeping-aid drug in Kerry Kennedy 's blood after a recent car accident , according to court documents . The final toxicology results show no alcohol and no drugs other than zolpidem , the generic name for Ambien . `` Moments after the accident occurred , I told police that it was possible that I may have inadvertently taken a sleep aid instead of my daily thyroid medication , '' Kennedy said in a statement released Wednesday . Police found Kennedy , 52 , daughter of the late Robert F. Kennedy and ex-wife of New York Gov . Andrew Cuomo , behind the wheel of her damaged Lexus SUV on the morning of July 13 . Kerry Kennedy charged in hit-and-run crash . A New York State Police press release said the SUV collided with a tractor-trailer . At a court hearing on July 17 in North Castle , New York , Kennedy pleaded not guilty to charges of driving while impaired . At a news conference after her court appearance , Kennedy said a partial seizure was the cause of the accident -- a seizure she said might have been from a previous injury she suffered on the right side of her brain . The judge released her under her own recognizance . She submitted to both blood and urine tests after the accident . Kennedy said she visited Mount Sinai Medical Center , where she underwent `` a full battery of neurological testing '' to understand her medical condition . Lucian Chalfen , a spokesman for the district attorney 's office in Westchester , declined to comment Wednesday , citing a pending case . In her statement , Kennedy said , `` I am deeply sorry to all those I endangered that day , and am enormously grateful for the support I have received over the past two weeks . '' According to the clerk for North Castle Justice Court , Kennedy 's case is adjourned until August 14 . Kennedy says seizure caused crash . CNN 's Dominique Debucquoy-Dodley contributed to this report .
Kerry Kennedy was involved in a crash early in the morning of July 13 . She told police at the scene that she might have taken a sleeping aid . She has pleaded not guilty to charges of driving while impaired .