The shooting happened around 11:30 a.m.
Police said Kortez Hurt, of Atlanta, shot another inmate in the hand.
Hurt was in jail for his 14th time, authorities said. His past charges include murder, drug possession and assault.
Fulton County Sheriff Ted Jackson declined a request by Reagan to answer questions about how an illegal gun got into the jail. Authorities said a small handgun was found near the area where the shooting took place.
But Channel 2’s Amy Napier Viteri got a call from an inmate inside the jail who was talking on an illegal cell phone. The inmate told Viteri that the dispute was over drugs and cigarettes. He said Hurt had paid another inmate for marijuana and cigarettes, but did not receive the items and became upset. The inmate said the halls of the Fulton County Jail are filled with contraband items.
Sources told the Atlanta Journal-Constitution that deputies searched the seventh-floor cell block where the shooting occurred and found 15-20 cellphones. It is illegal for inmates to have cellphones in the jail.
The midday shooting sparked a lockdown and evacuation of the jail of all non-essential employees
Regan caught up with several employees as they were leaving the jail.
One told him that he was surprised by the shooting.
I think its terrible. How could have they have gotten a gun in the jail? Someone aint doing the job, said John Savors, a jail visitor.
Denice Nash told Regan that they were given little information about the incident.
They just locked down the place and told everyone to leave, said Nash.
Employees were allowed back inside approximately 2½ hours after the lockdown.
The Sheriffs Office said the alleged gunman will face assault charges. The wounded inmate suffered non-life-threatening injuries and was treated at the jail infirmary.