A man was shot and killed at a South Fulton apartment complex early Thursday morning, a little more than 12 hours after another deadly shooting in the city, officials said.

A suspect has been arrested following the deadly shooting at the Westwood Glen Apartment Homes in the 1200 block of Fairburn Road, police spokeswoman Ashley Minter-Osanyinbi said in an emailed statement.

South Fulton police Maj. Sheila Rogers told reporters on the scene that the suspect, a male, called 911, stayed at the complex and later told police “that he had messed up.”

She said there was an altercation between the suspect and victim shortly before the gunfire erupted at 8:27 a.m.

“There are no names at this time and City of South Fulton Police are actively conducting an investigation,” Minter-Osanyinbi said. “More details will be provided as soon as possible.”

The relationship between the suspect and victim is unknown, Rogers said, although they were not strangers.

Police said the deadly shooting is not connected to another in South Fulton. In that case, witnesses at a shopping center in the 5000 block of Old National Highway told police they saw a gunman in a hooded sweatshirt fire at a man while he was on his cellphone about 8:15 p.m. Wednesday. The victim, identified by the Fulton County Medical Examiner’s office as 24-year-old Jeremiah Wyatt of College Park, died at the scene.

“Unfortunately, these are occurrences that have happened, and we are investigating to make sure those persons are brought to justice,” Rogers said.

Police said the victim was on his cell phone when it happened.

RELATED: Police investigate deadly shooting at busy South Fulton shopping center

Police have not made an arrest in Wednesday’s deadly shooting.