ATLANTA -- The police officer who opened fire and injured a North Carolina man while directing traffic near the Georgia Dome has been fired, officials confirm.

Sgt. Mathieu Cadeau was let go from the Atlanta Police Department on May 8 following the conclusion of a GBI investigation, according to a spokesperson for the department.

In March, Cadeau was directing traffic outside of a motorcross event at the Dome when he shot 46-year-old Noel Hall as he and his family were leaving the event. Hall had called the incident "absolutely unjustified."

PHOTOS | Cop shoots man driving in downtown Atlanta

According to an initial investigation by the Georgia Bureau of Investigation, Cadeau had ordered Hall to go in one direction down Northside Drive, but Hall reportedly wanted to go in another direction. Hall then tried to turn onto Ivan Allen Jr. Boulevard and drove toward Cadeau. That's when the sergeant opened fire, hitting Hall in the arm and barely missing his wife's head in the passenger seat.

PHOTOS | Man shot by Atlanta officer injuries; graphic content

It's still unclear at this time, why Cadeau opened fire at all. According to officials, he was serving as a hired security guard outside event when the shooting happened. At the time, police had not indicated whether Cadeau, who was a member of APD's field operations division, felt threatened.

In a press conference, Hall and his family said they couldn't understand how an interaction between him and the Cadeau escalated and ended in gunfire. He said they intended to look for justice.

Cadeau had been with the Atlanta Police Department since 2007, according to his personnel file. According to that file, he had been cited multiple times for "maltreatment or unnecessary force" and had previously had another "violent confrontation" with another Atlanta couple in 2013.