The Forsyth News reports 48-year-old Scott Biumi pleaded guilty to two counts of aggravated assault in the April 9 incident.
Surveillance footage from inside a suburban Atlanta McDonald’s showed Biumi pointing a gun through another driver’s window as he leaned into it during the argument.
Authorities have said Biumi was upset the driver ahead of him was taking too long at the window.
As part of a plea agreement, Biumi — a 26-year law enforcement veteran — is barred from owning a firearm or working in law enforcement.
Biumi must also do 120 hours of community service during his first year of probation.