What led Oklahoma woman to crash into crowd at homecoming parade?

A young Oklahoma woman will make her first court appearance Monday after being charged with killing four people and injuring dozens of others by driving her car into a crowd at the Oklahoma State University homecoming parade Saturday.

The annual celebration turned into a horror scene when Adacia Avery Chambers, a 25-year-old from Stillwater, “barreled” her car into a street corner packed with about 100 people who were starting to disperse after the parade ended, police say.

"We were facing the parade and heard tires squealing and then started to hear the car hitting things and people and there was screaming and people running away," Megan Lantz, who said her family was sitting across the street from where the car careened into the crowd, told The Oklahoman.

Ms. Chambers was arrested on Saturday for driving under the influence, and held in custody over the weekend on four counts of second-degree murder, according to a statement from the Stillwater Police Department.

Three people were pronounced dead at the parade; a two-year old boy died later at the hospital after being injured at the event. Forty-six other people were injured in the collision, said Stillwater police.

Chambers’ attorney, Tony Coleman, said at a press conference in Oklahoma City over the weekend that the young woman likely suffers from mental illness and that she did not drink alcohol before the event.

"I absolutely can rule out alcohol," Mr. Coleman said.

Police are waiting for results of tests to identify whether there were traces of drugs or alcohol in Chambers’ blood.

During his hour-long interview with Chambers, said Mr. Coleman, “I was not satisfied at all that I was communicating with a competent individual."

Chambers left work at Freddy's Frozen Custard & Steakburgers in Stillwater before the crash, according to Coleman, and has a murky recollection of what happened. She remembers only being removed from the Hyundai Elantra she was driving and being confused.

Besides the 2-year-old boy who died in the hospital, those who died on the scene were Nakita Prabhakar, a graduate business student at the University of Central Oklahoma in Edmond, and Marvin Lyle Stone, a retired professor of agricultural engineering at OSU, and his wife Bonnie Jean Stone.

Hundreds of people gathered for a candlelight vigil at Oklahoma State University in Stillwater Sunday night to honor those who were lost, reported KOKH, and comfort one another.

This report contains material from Reuters and the Associated Press.