A woman will spend 20 years in prison and 35 years on probation for hitting and killing a 71-year-old pedestrian, crashing into numerous vehicles and carjacking other vehicles in 2016.

Kristie Renee Nesby last Wednesday entered a plea of guilty but mentally ill to 10 charges, including homicide by vehicle, armed robbery, hijacking a motor vehicle, hit-and-run, aggravated assault and possessing a firearm during the commission of a felony, Cobb County District Attorney spokeswoman Kim Isaza said Tuesday in a statement.

RELATED: Driver caught in Atlanta after fatal accident, carjackings in Cobb

Nesby, 45, of Fresno, Texas, had been scheduled to go to trial Oct. 15 in connection with a bizarre string of events that began shortly after 5 a.m. May 11, 2016, in Cobb County and ended later that morning in front of the Majestic Diner in Atlanta.

According to prosecutors, Nesby first approached the owner of a cleaning company as he finished his morning routine at a Smyrna business, produced a handgun, ordered the man to the ground, and demanded his wallet and car keys.

She was later spotted driving at a high rate of speed down I-575, where she hit a vehicle without stopping, traveled the wrong direction up the southbound exit ramp and struck a second vehicle without stopping.

Shortly after 6 a.m., Nesby drove off the roadway and onto a sidewalk on Cobb Parkway near Bells Ferry Road, where she hit pedestrian Luci Turner, authorities said. Turner, who eventually died from her injuries, was walking to her job at Burger King at the time of the crash, according to officials.

The crime spree spilled over from Cobb County to Fulton County after Nesby carjacked a vehicle on Bells Ferry Road, sped down I-75, hijacked a second vehicle and robbed another woman of her cellphone at gunpoint.

“While driving to Atlanta, Nesby called 911 and told the operator that she would take a hostage and then kill both the hostage and herself unless police chased her with blue lights and stopped her,” Isaza said. “She said someone had put something into the air that was affecting her organs, and she also stated that an employee of a fast food restaurant had put something in her drink the night before that was causing her to hallucinate and commit these crimes.”

MORE: Chick-fil-A drink led to deadly crime spree, woman says

Before officers arrested her in Atlanta, prosecutors said Nesby crashed into numerous vehicles on North Avenue in Atlanta, went off the roadway, hit landscape that immobilized the vehicle she was driving, and attempted but failed to hijack another vehicle.

ALSO: No bond for suspect in fatal crash, carjackings in Cobb

“Investigators found that she was armed with two handguns throughout her crime spree,” Isaza said. “Nesby’s blood tested negative for any drugs and alcohol.”

Defense attorneys and prosecutors asked the court to find Nesby mentally ill. They also asked the court “to determine that although Nesby may have been experiencing delusional compulsions that overmastered her will, the delusional compulsions, if real, would not have justified her unlawful acts,” Isaza said.

Cobb Superior Court Judge Stephen Schuster agreed to the requested findings and accepted Nesby’s plea.

Nesby will receive mental health treatment in prison as well as credit for the time she has served since her arrest, Isaza said.

In other news:

The girl underwent surgery at Grady Memorial Hospital Tuesday morning.