According to the Associated Press, police have announced that Adacia Avery Chambers, a suspect in the fatal car crash at Oklahoma State’s homecoming parade on Saturday, is being held on four charges of second-degree murder.

Chambers was taken into custody on suspicion of driving under the influence of alcohol or narcotics, police said. She is expected to make an appearance at Payne County District Court Monday.

While police await the results of a toxicology test, Chambers’ lawyer, Tony Coleman, told a press conference that there was no reason to believe she had been drinking or taking drugs: “In my opinion, Ms. Chambers suffers from a mental illness.” He also said that Chambers had recently been unable to sleep.

“I absolutely can rule out alcohol,” Coleman said. “She doesn’t remember a whole lot about what happened. There was a period where I think... she could have even blacked out.”

One of the four people killed was a two-year-old boy, and 47 other people were injured, Reuters reports. Five were in critical condition Sunday.

“All I remember was a gush of wind and then the sound,” said Mark McNitt, who was standing with his stepfather when what police say was Chambers’ gray Hyundai Elantra tore into the homecoming crowd.

“The only thing I can relate it to is some type of bombing,” McNitt told Reuters. “The screaming... and a lot of chaos.”

Photo credit: AP Images. Contact the author of this post: brendan.oconnor@gawker.com.