The car traveled a short distance before crashing into two parked vehicles, the GBI said. Officers found Griffin dead in the vehicle.
Simmonds had a minor injury to his foot but was not shot, the news station reported.
Atlanta police spokesman Officer Jarius Daugherty said Simmonds was hired by the department on April 29, 2010. His status with the agency was not released.
The GBI said there’s no evidence the man was armed with any kind of weapon, and he might not have realized he targeted a police car because it was unmarked.
The WSB 24-hour Traffic Center reported police temporarily blocked the I-20 eastbound exit ramp to McDaniel as well as the street’s intersection with Whitehall to investigate the incident.
The GBI continues to investigate the officer-involved shooting. This is the sixth such investigation the agency has opened in 2019, and the second deadly police shooting this week.
RELATED: Georgia sees spike in deadly police shootings in 2018
OVER THE LINE: Police shootings in Georgia
Police shot and killed patient Rodney Hamilton, 62, of Dahlonega, after he held people hostage at gunpoint inside Lanier Dermatology on Monday morning, the GBI said.
RELATED: Police shoot, kill gunman at dermatology office in Gainesville, officials say
MORE: Dermatology patient ID'd as gunman killed in Gainesville officer shooting
— Please return to AJC.com for updates.