"She stepped on the accelerator and went straight for him," Lindsey Harris, 17, said at her stepmother's murder trial. "He was really scared. He was trying to get away and he couldn't."
Clara Harris, 44, is accused of intentionally running over her husband, David Harris, in a hotel parking lot July 24. She has said her husband's death was an accident.
Lindsey Harris testified that her father confessed to his wife days before his death that he was having an affair with one of his office workers, Gail Bridges.
The teenager said she and her stepmother starting searching for David Harris on July 24 because Clara Harris believed her husband was still sneaking off to meet Bridges.
Under cross examination by defense attorney George Parnham, Lindsey Harris told jurors she has filed a wrongful death lawsuit against her stepmother.
The teenager said she partially blamed the affair on her stepmother's lack of attention to her father, but said she told her father he should not leave her stepmother for Bridges, whom she described as fake and "the personification of evil."
Prosecutors say Clara Harris was enraged because her husband chose his mistress over his wife.
Lindsey Harris testified her father was struck once and then her stepmother circled around and hit him two more times, never trying to avoid him. The teenager said she jumped out and hit her stepmother when the car finally stopped.
"I knew she had killed my dad," she testified as Clara Harris sat with her hands covering her face.
"She said, 'I'm so sorry. I'm so sorry. It was an accident.' She knew what she did and she wasn't sorry."
Lindsey Harris also told jurors that her stepmother had told her just before her father's death that "she could kill my father for what he's done and get away with it."
Last week, the jury was left with the shocking image of the hulking vehicle in the parking lot as it repeatedly ran over the body of the victim.
As CBS News Correspondent Elizabeth Sanchez reports, a tearful Clara Harris watched with jurors the tape showing her driving erratically in a hotel parking lot after confronting David Harris and his mistress. The amateur photographer is a former employee of Blue Moon Investigations, the firm hired by the defendant to follow her husband.
If convicted, Clara Harris faces up to life in prison. If jurors determine she acted under the legal definition of sudden passion, they could consider a lighter sentence of two to 20 years in prison.