The St. Louis Metropolitan Police Department said the shooting occurred Friday night in the city's downtown area. Sources briefed on the investigation told CNN that a police report identified the victim as 26-year-old Becca Campbell.
The sources told CNN that the victim was involved in a car accident. Campbell's 33-year-old boyfriend, who was not identified, was driving the car and told investigators that Campbell began waving a gun around and joking that the couple were ready for Ferguson, the sources said.
The boyfriend said he rear-ended another car while ducking to avoid the gun, which then discharged and struck Campbell in the head, the sources said. The victim later died at a hospital.
The boyfriend told police that the couple purchased the gun because they feared unrest that may arise from a grand jury decision in the fatal shooting of unarmed black teen Michael Brown by a white police officer, the sources said.
Police were investigating whether the boyfriend's account of the shooting was correct, the sources told CNN.