When a group of men stole 86 guns from Autrey’s Armory Dec. 5, they forgot to steal equally important parts: The magazines that hold and feed ammunition to the weapons.

Ultimately it was that faux pas that led to the arrest of all nine suspects tied to the smash-and-grab burglary of the gun store off Ga. Highway 314 at Bethea Drive, police announced Monday afternoon.

“They had to buy magazines to make them working guns,” said Investigator Josh Shelton of the Fayette County Sheriff’s Office.

Each of the nine are from Riverdale and are alleged members of the Southside Mafia gang, police said.

Only a few of the guns have been recovered so far. But now there’s a $2,000 reward for information leading to the location of the guns or information leading to the people in possession of the weapons.

As many as eight sheriff’s detectives worked on the case at any one time, pulling long days as they knocked on doors in Clayton County asking questions and looking for clues ... anything suspicious that might lead to the suspects.

From the start they had little to go on but a low-quality surveillance video that showed how methodically the group conducted the burglary, police said. It didn’t show any of their faces well enough to have any of the suspects identified, police said.

But the old-fashioned detective work paid off, as leads kept rolling until all nine suspects were arrested, Shelton said.

All have been ordered to be held in jail without bond pending their trial.

Fayette detectives said the cooperation from other law enforcement agencies was invaluable, particularly lauding the federal Bureau of Alcohol, Tobacco and Firearms, the Clayton County and DeKalb County police departments, the U.S. Marshals Southeastern Fugitive Task Force and federally licensed firearms dealers.

Although the nine suspects all face burglary charges, it’s possible they may be prosecuted at the federal level where it’s a crime to steal guns from a federally licensed firearms dealer, said ATF Special Agent Marc Jackson. He noted that the U.S. Attorney’s Office and the Fayette County District Attorney’s Office are involved with the case.

“Suffice it to say this investigation is far from over,” Jackson said.

Getting the stolen guns back is of significant importance because they are more likely to be used in crimes, Jackson said.

“Firearms enthusiasts don’t steal from gun dealers,” Jackson said. “Felons, gang members and juveniles do.”

One of the suspects arrested was 16 years old and is already serving a detention sentence, police said. The others arrested include Melvin “Melvo” Johnson, Kissan “Big Boy” Lynch, Roland “Gucchi” Williams, Brandon “Mickey Mouse” McClure, Fredrick “Fred” Anderson, Cornelius “Trigger Boy” Heard and Anthony “2 Tall” Alston.

Each was charged with felony burglary.

Alston turned himself in Monday morning after learning on the street that the fugitive task force was on his trail.

The suspects’ alleged connections to the Southside Mafia gang is significant in part because that gang was also implicated in the 2004 shooting at a Riverdale park that resulted in the death of a young child, police said.

The suspects used a stolen truck from Clayton County to pull the burglar bars off the business to gain entry. Once inside they smashed glass cases and used bolt cutters to wrest the guns free, tossing them into a plastic garbage can. The whole burglary lasted just a few minutes.

Shelton posted the surveillance video on YouTube in an effort to drum up tips from the community. In addition to the outstanding cooperation from other agencies, he also lauded the hard work of his fellow Fayette detectives.

“If not for these people working their tails off every day, it would not have gotten done,” Shelton said.