Kimberly Dorsey's lawsuit, filed Thursday in the Illinois Court of Claims, accuses Trooper Matt Mitchell, the state and the Illinois State Police of negligence and seeks $24 million in damages.
Mitchell's cruiser crossed the median of Interstate 64 and slammed into the car carrying 18-year-old Jessica Uhl and 13-year-old Kelli Uhl in November. The Collinsville teens, returning from a holiday photo shoot, died at the scene.
A coroner's jury ruled the deaths reckless homicide after an accident reconstructionist testified Mitchell was traveling 126 mph just east of St. Louis when he lost control of his police car.
Mitchell, 30, has pleaded not guilty to reckless homicide and aggravated reckless driving. He is free on bond but has been relieved of his trooper duties.
"One of the things that obviously is preached by Illinois State Police as a law enforcement agency is that people have to be accountable for their actions," said Dorsey's attorney, Tom Keefe Jr. "The message of this case is that accountability goes both ways."
Mitchell's attorney, John O'Gara, did not return telephone messages Friday. A state police spokesman said the agency had not seen the lawsuit and generally does not publicly discuss litigation.