The Oklahoma woman facing four second-degree murder charges after allegedly driving into a homecoming parade crowd was described on Monday as a “cautious” driver who never even ran a yellow light.

Adacia Chambers was held on $1 million bond during an arraignment Monday. The judge also ordered a psychological evaluation.

Chambers was not formally charged with the four murder counts, as prosecutors said one of the other 46 people she’s alleged to have injured is still clinging to life. Each murder count could carry a maximum penalty of life in prison.

But as authorities search for why Chambers allegedly drove her car into the crowd at the Oklahoma State University homecoming parade on Saturday, her family and friends provided few clues during a Monday news conference.

Though Chambers was arrested after Saturday’s crash on suspicion of driving while under the influence, attorney Tony Coleman said Chambers did not smell of alcohol or appear to act drunk when he met her hours after the accident.

More On This...

“I absolutely can rule out alcohol,” Coleman said Sunday. Police are awaiting the results of blood tests to determine if Chambers was impaired by alcohol or drugs.

Chambers’ boyfriend, Jesse Gaylord, also told reporters he had never seen her take prescription medication and that the couple “rarely” drank and never used drugs.

“There’s no way she was drunk or impaired,” Gaylord said.

Gaylord said he never saw Chambers black out and wasn’t aware that she had been having any car trouble, also noting that she had a sterling driving record. Though he said Chambers told him she hadn’t slept well the night before the crash, he said “everything seemed fine” as he hugged and kissed her on Saturday morning and told Chambers to “have a good day at work.”

“I don’t know how this happened,” Gaylord said.

According to the Oklahoman newspaper, however, Chambers suffered from insomnia and had not slept for three days before the crash.

Chambers’ father, Floyd, said his daughter may have had problems he “wasn’t fully aware of,” but he still tearfully struggled to understand what led to the “tragic accident.”

“The little girl I raised wouldn’t have done something like this,” he added.

The Stillwater News Press reported that a witness saw Adacia Chambers leaving her job at a local fast-food restaurant only one hour into her shift Saturday morning. The witness told the paper that Chambers may have been crying. However, Chambers' manager told the paper that she appeared to be fine when she left.

Coleman has said he believed the 25-year-old fast food worker may be suffering from a mental illness.

"She doesn't remember a whole lot about what happened. There was a period where I think ... she could have even blacked out," Coleman said of Chambers. The attorney said Chambers only recalls people removing her from the car and being extremely confused.

"I have deep concerns about her competency at this point," Coleman added. "I'm not a psychologist or psychiatrist, but I can tell you she's suffering from mental illness."

Witnesses of the crash described a scene of chaos as bodies flew into the air from the impact and landed on the road. The deceased have been identified as Nash Lucas, 2, Nakita Prabhakar Nakal, 23, and a married couple, Bonnie Jean Stone and Marvin Lyle Stone, who were both 65.

It's not the first tragedy to strike events connected to Oklahoma State sports programs. Ten people, including two OSU men's basketball players, were killed in a 2001 plane crash while returning from a game in Colorado. And Oklahoma State women's basketball coach Kurt Budke and assistant Miranda Serna were among four killed in a plane crash in Arkansas in 2011 while on a recruiting trip.

The Associated Press contributed to this report.