Dontae Morris needed a ride, so Cortnee Brantley picked him up.
The couple had dated on and off, but were just friends that fateful Tuesday, Brantley's mother said Saturday.
Police say Brantley, 22, drove away after Morris shot and killed Officers David Curtis and Jeffrey Kocab after a traffic stop revealed a warrant for his arrest.
Mischell Brantley said fear made her daughter run.
"She was scared for her life," she said. "She's very sensitive."
Now, her daughter sits in the Hillsborough County Jail charged with misprision of a felony, a federal law that makes it illegal to witness a convicted felon commit a crime and not report it.
Mischell Brantley hasn't seen her daughter since she was arrested Friday at a Brandon apartment complex. "I'm devastated, as any mother would be," she said.
"She's the type of person to run and think that it's over," her mother said. "Like if she just closed her eyes it would just go away."
Before Tuesday, Cortnee Brantley had never been in serious trouble with the law.
Her mother said she had some difficult years in her teens and didn't graduate from Armwood High School.
But her soft-spoken daughter earned her GED and went out into the working world, taking on two to three jobs at a time, as Mischell Brantley had done to raise her two girls.
"She was taking a full load of classes at Hillsborough Community College," her mother said.
The sensitive young woman formed a tight-knit trio with her mother and 17-year-old sister.
"We are very close. It's always been just the three of us. My 17-year-old is devastated. She can't sleep and hasn't been able to eat," Mischell Brantley said.
When police came Tuesday looking for Cortnee Brantley, her mother was certain she had not killed anyone. "I have exotic fish and she cries every time one of them died," she said.
But she doesn't absolve her daughter from blame.
"Sometimes good girls have dated bad guys," she said. "I would just say that some kids are more easily led."
As she was being questioned Tuesday, Cortnee Brantley accepted her role in the incident.
"She said 'If I had known what would happen I would have never given him a ride,'" her mother said.
Her mother said that Cortnee never saw or spoke with Morris after he ran from the shooting that night. "When they parted ways, they never saw each other again."