The Jacksonville Sheriff's Office says 24-year-old Sahara Barkley was killed late on New Year's Day.
According to news reports, store clerk Nyla Garner said Barkley had left her vehicle running, and it was taken by a man.
Garner says Barkley confronted a woman who was with the man, and gunfire followed. Garner rushed to help Barkley.
She said Barkley kept saying, "Please don't let me die, I got a baby."
The department released surveillance video showing a woman whom detectives are trying to identify.
The Florida Times-Union reports that Barkley's family confirmed her death and thanked Garner for trying to save her life.
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