A judge ordered a psychological evaluation Monday for an Oklahoma woman accused of driving her car into an Oklahoma State University parade, killing four people and injuring dozens of others.

Payne County Special District Judge Katherine Thomas also set bond at $1 million for Adacia Chambers, who is being held on four preliminary counts of second-degree murder as prosecutors consider formal charges.

Chambers appeared at Monday's hearing via video. The only time she spoke was to say "yes" when the judge asked if she could hear her.

Prosecutors asked for more time to interview the dozens of witnesses who were at the scene and said one of the injured is in a "fragile" state, which could lead to more charges.

The parade was part of Homecoming activities at the university. Homecoming is the tradition of welcoming back a school's alumni and takes place at many U.S. universities, colleges and high school. It usually includes sports and cultural events and a parade.

Adacia Avery Chambers

Adacia Chambers is facing four counts of second-degree murder. Prosecutors still have to file documents in Payne County District Court to formally charge the 25-year-old, who is accused of killing 4 and injuring dozens. (Stillwater Police)

The judge scheduled the next hearing for Nov. 13.

In Oklahoma, second-degree murder charges are warranted when someone acts in a way that's "imminently dangerous to another person" but does so without premeditation. Each count is punishable by at least 10 years in prison.

Chambers, 25, has yet to be formally charged — an additional step that requires prosecutors to file documents in Payne County District Court.

Her attorney, Tony Coleman, told NBC's Today show Monday that Chambers had "no real response whatsoever" when he told her that four people died as a result of Saturday's crash. He said he believes she is mentally ill and said she was hospitalized two years ago for an undisclosed mental illness.

Coleman said Chambers' family is "absolutely devastated" by the crash.

Homecoming Parade Crash in Oklahoma

Emergency personnel and spectators respond after Saturday's crash. (David Bitton/The News Press/Associated Press)

"Their thoughts and their prayers seem to be more-so focused on the victims and the family members of the victims of this horrible incident, and that's something that they wanted to make sure was communicated over and over again," Coleman said.

On Sunday, Coleman said there was no indication that Chambers had been drinking before the crash. Police are awaiting blood tests to determine whether she was impaired by drugs or alcohol.

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

He said he spoke with Chambers for about an hour.

"During that entire interview, I was not satisfied at all that I was communicating with a competent individual," Coleman said.

APTOPIX Homecoming Parade Crash

Oklahoma State students Kelly Cooke, right, and Rebecca Buchanan read messages on a memorial in Stillwater, Okla. (Sarah Phipps/The Oklahoman/Associated Press)

He said Chambers was at work before the crash and that she does not remember much of what happened, only that she felt confused as she was removed from the car.

"She could have even blacked out," Coleman said.

Chambers' father, Floyd Chambers of Oologah, told The Oklahoman newspaper Saturday that he could not believe his daughter was involved and that she was not an alcoholic. He could not be reached for comment Sunday by The Associated Press.

Three adults and a 2-year-old boy were killed and at least 46 other people hurt, including many children.

On Monday, the Oklahoma medical examiner's office identified the boy killed in the crash as 2-year-old Nash Lucas. Oklahoma State University said the boy's mother, 20-year-old Nicolette Strauch, is a sophomore majoring in chemical engineering.

Homecoming Parade-Crash

The car involved remained in a cordoned-off area while police investigated. (Brody Schmidt/Associated Press)

The dead adults were identified as Nikita Nakal, a 23-year-old MBA student from India at the University of Central Oklahoma in Edmond, and a married couple, Bonnie Jean Stone and Marvin Lyle Stone, both 65, of Stillwater.

All four died from multiple blunt-force injuries, said Timothy Dwyer, the Oklahoma medical examiner's office chief investigator.

Marvin Stone was a retired professor of agricultural engineering, who had been popular with students, a colleague said.

"He was loved by students and one of the best teachers we had," said Ron Elliott, the former head of the Biosystems and Agricultural Engineering Department at OSU. "He just really had a gift for connecting with students and helping them learn," Elliott said in a telephone interview.

OSU said Bonnie Stone had worked in the university's institutional research and information management department.

Konda Walker, an OSU graduate who was in Stillwater with her sister to celebrate homecoming, said she was only about 50 feet from the crash scene.

She said it took her a few seconds to process what had happened. There were bodies and injured people lying "all over the place," Walker said.

"One woman was a crumpled mess on the road. They turned her over and started CPR. We realized she didn't make it," she said.

Among the injured were nine children 10 years old or younger.