CBS News affiliate WGCL-TV reports that Herbie Deshawn Durham was charged Wednesday night with two counts of murder.
"The walls are beginning to fall down around the ones who committed this crime," said DeKalb Police Chief Terrell Bolton at a news conference Wednesday night.
At least one more person wanted by police is still on the run.
Police had combed the area in search of two gunmen Wednesday after two off-duty DeKalb County officers were killed in a possible ambush at an apartment complex in what residents described as a high-crime neighborhood.
The two officers, working as security guards at the complex, were investigating a suspicious person at the complex when shots were fired early Wednesday, DeKalb County Police Chief Terrell Bolton said.
Authorities had been searching for two males seen running from the scene. Police used dogs and a helicopter to search for the suspects, and schools were locked down during the investigation in the area about 6 miles east of downtown Atlanta.
He told reporters the dead officers were wearing their police uniforms.
Bolton said the shooting looked like "an ambush."
"They never had a chance," Bolton said, reports WGCL-TV. "What a horrible, horrible way to die."
At an afternoon news conference, Bolton called the shootings a "must-solve crime" and urged witnesses to come forward.
Bolton did not say whether the officers had a chance to return fire before they were killed and he did not say what led to the shooting.
Meanwhile, a reward offered for information about the slayings of two off-duty DeKalb police officers has increased to $60,000, police announced Wednesday night.
"These police officers were heroes, they were committed and dedicated to law enforcement," Jones said. "We will not rest until those folks responsible for this are apprehended and justice is served."
Patreka Anderson, a resident of the complex, said she was awakened by the gunshots but did not think anything of it because the neighborhood around the Glenwood Gardens apartment complex is a high-crime area with a lot of drug activity and prostitution.
"We always hear shooting," she said. "I didn't think that was any big deal."
Teofil Taut, who said he has owned the 176-unit complex for about two years and lives in one of the buildings, said he hired police as part-time security officers in December to keep homeless people from breaking into the apartments.
Another resident, nurse's assistant LaShawn Corbin, said she is considering moving, even if it means paying more for an apartment.
"We don't expect the people who try to protect us to be hurt so seriously," she said. Corbin said she would fear leaving her children there "because the person who did it has no conscience for human life."
The slain officers were identified as Ricky Bryant, Jr., 26, and Eric Barker, 33. Bryant was a two-year veteran of the department, and Barker had worked there for four years. Both were married and had four children each
"It's a challenging day for us," Bolton said. "However, today's act of senseless violence is a display of what we're seeing around the country where people will shoot down a police officer without regard to any repercussions."
© MVIII, CBS Interactive Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report