An Oklahoma woman has been charged with four counts of second-degree murder a day after she allegedly crashed the car she was driving into a crowd at an Oklahoma State University homecoming parade, killing four people and injuring dozens.
Adacia Avery Chambers, 25, allegedly drove a gray Hyundai Elantra into a throng watching Saturday's Oklahoma State University homecoming parade in Stillwater, about 105 kilometres southwest of Oklahoma City.
Three adults and a toddler were killed and dozens were injured. Police said they suspected she was intoxicated.
Her lawyer, Tony Coleman, told The Oklahoman newspaper he believes his client is mentally ill and doubted she was drunk at the time of the crash.
"I don't believe right now that she was intoxicated," Mr Coleman told the newspaper.
"I have deep concerns about her competency at this point. I'm not a psychologist or psychiatrist, but I can tell you she's suffering from mental illness."
Reuters could not immediately reach the attorney. She was expected to make an initial appearance in Payne County District Court on Monday afternoon, police said.
About four dozen people were injured in the incident, five of them critically.
A man who was watching the parade with his family said the crash sounded like a bomb went off, transformed a festive mood into one of horror.
"All I remember was a gush of wind and then the sound," Mark McNitt said at a news conference, recalling when the vehicle jumped the curb, mowing down dozens of men, women and children.
"The only thing I can relate it to is some type of bombing," said Mr McNitt, whose father-in-law Leo Schmitz, 54, was critically injured. "The screaming ... and a lot of screaming."
Police were awaiting results of a blood test administered to Ms Chambers after the crash.