MONTGOMERY COUNTY, Pa. (CBS) — The Montgomery County District Attorney’s Office says the woman accused of hitting and killing firefighter Thomas Royds on the side of Schuylkill Expressway earlier this year was driving a car without rear brakes, not under the influence as previously stated.

DA Kevin Steele, along with officials from Pennsylvania State Police and Lower Merion Township, gave an update Tuesday on the investigation into the July crash that killed firefighter Thomas Royds and injured three other first responders.

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On July 24, Royds and other first responders were assisting with a two-vehicle crash on Schuylkill Expressway when authorities say Jacquelyn Walker, 63, drove her Jeep Grand Cherokee up the right shoulder.

“This crash on the 24th is every first responder’s nightmare,” DA Steel said. “And I should add it’s the nightmare of every first responder’s family as well,” Steele said.

According to DA Kevin Steele, all the emergency vehicles arrived to the scene with their lights on and kept them on. Firefighters with the Belmont Fire Department did put out cones to have traffic move around the scene.

Jaquelyn Walker failed to follow directions to drive in the opposite lane and “plowed” into Royds, two other firefighters, and a Pennsylvania State Trooper. She proceeded to drive into the Nissan involved in the crash, pushing the car 30 feet.

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Steele said the Jeep Walker was driving was “in poor condition” and rusted through. The rear brakes of the car didn’t work, and one front brake partially worked. Troopers originally said Walker admitted to drinking mixed drinks at the time of the crash. However, toxicology reports said she was no under the influence of anything at the time of the collision.

Authorities said Walker knew about the condition of the car but drove it anyway.

“She wouldn’t have been in that situation had she not been driving the car number one, and not disregarded all the indicators where she should go,” Steele said.

Walker will now be charged with third-degree murder, aggravated assault, and homicide by vehicle. She could face enhanced sentencing for crashing into an emergency area. A preliminary hearing is scheduled for next week.

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CBS3’s Alecia Reid contributed to this report.