One of the officers was shot in the leg as was the homeowner. The home owner's dog was killed in the firefight
The homeowner was also shot in the leg and the homeowner's dog was killed.
It's not clear yet who fired the shots. Alexander says the Georgia Bureau of Investigation has been called to investigate.
The shooting happened in a neighbourhood about 5 miles from downtown Atlanta.
Police received what is being described as a 'vague' call about a burglary in progress when officers responded.
Alexander said the officers identified themselves before entering the house.
The officer was undergoing emergency surgery after losing 'a lot of blood' after being hit in the thigh.
The Georgia Bureau of Investigation is going to handle the investigation.
The seriously wounded officer, who has not been named, is being treated in the Grady Memorial Hospital.
Alexander told NBC what the caller only gave a partial description of the property under threat claiming it was a 'grey brick house'.
Officers were not given a street number.
He added: 'Shortly after that, within a matter of moments, gunfire took place.'
The officer and the home owner were both shot in the leg, while the pet dog was fatally wounded.
He continued: 'A lot is yet to be determined here as to what [happened] and when shots were fired, how the officer received injuries, how the homeowner received injuries. But we did respond to the wrong residence tonight.'
Alexander admitted that it was not clear whether the homeowner had a gun, describing the situation as 'complicated'.
Three officers responded to a house that fitted the description of the home supplied by the 911 caller.
They went around to the rear of the property and discovered the rear door and screen door were unlocked.
He said: 'That in and of itself would probably suggest to anyone that it is possible that there could be intruders inside, but it turned out not to be the case. 'Somewhere at the rear of that home, some things happened that have yet to be determined."
The officers had just entered the home when the gunfire erupted.
He continued: 'There was gunfire, I just cannot tell you who fired and who did not.'
An officer was shot in the leg and lost a lot of blood. He was rushed to the hospital and was undergoing surgery. The homeowner was also taken to the hospital.
The homeowner's girlfriend was at the home at the time of the shooting and called 911.
Derek Perez told The Associated Press that he reported the suspicious person. He said he was walking his dog when he saw a man knock on a neighbour's door and then just stand in the yard. He said he then heard a loud noise, a dog barking and didn't see the man anymore. There had been break-ins in the neighborhood recently, so he called 911, he said.
Just as he was about to go into his house, he heard the gunshots, but they didn't come from the house where he had reported the suspicious person.
Police were still investigating whether there was a burglary at the home where the suspicious person was spotted.
All three officers have been placed on administrative leave.
The shooting happened in a neighborhood about 5 miles from downtown Atlanta.