With all of the suspects in recent cellular phone store robberies in Gwinnett and DeKalb counties now in custody, police Wednesday said they are looking at possible connections between the latest heists and a series of stick-ups two years ago.

Charles Hamm, Antonio Robert Watson, Eldrico Sylvester Derrico and Anthony Digby are being held without bond on armed robbery and other charges in DeKalb County Jail, authorities said.

They are suspected of at least seven armed robberies, mostly of MetroPCS stores, since mid-August.

In every robbery, the set-up was the same: One man would come into a store, pretending to be a customer. Another would follow a few minutes later, acting as though he was talking on a cell phone – until he turned around and pointed a gun at the store clerk.

"They're only demanding cash, no phones … trying to get out as quick as they can," Snellville police Detective Cpl. James McDonald told Channel 2 Action News.

Snellville’s investigation began Sept. 14, when bandits struck a MetroPCS store in New London Plaza off Henry Clower Boulevard.

Two men robbed the store, forced the employees into a bathroom and left out a back door, getting away in a 2001 Chevrolet Monte Carlo driven by a third man and waiting in a gas station parking lot next door.

“We were able to develop information working with the Dekalb County (Police) major felony unit, the DeKalb County Sheriff’s fugitive division … and through informants as well,” McDonald said in a phone interview with the AJC.

The DeKalb agencies "were instrumental in helping us crack this case," McDonald said. Additionally, he said, store  surveillance video “helped us narrow down who we were looking for."

One break came on Sept. 28, when DeKalb authorities arrested Digby, 20. He was charged with armed robbery.

The second came Oct. 5, when Hamm, 24, was arrested by the DeKalb Sheriff’s Fugitive Squad and U.S. Marshal’s Special Task Force after an hour-long standoff at a home in Decatur. Hamm is Digby’s cousin, McDonald said.

Hamm was charged with one count each of armed robbery, possession of a firearm by a convicted felon and possession of a firearm in the commission of a felony, and two counts of false imprisonment – for allegedly forcing the two store employees into the bathroom.

Following the investigative trail to Hamm’s acquaintances, police arrested Derrico, 23, on Friday, and Watson, 23, on Tuesday. Both were taken into custody without incident.

Each man was charged with armed robbery, aggravated assault, possession of a firearm in the commission of a felony, and two counts of false imprisonment. Watson also was charged with possession of a firearm by a convicted felon.

But the investigation doesn’t end there.

“About two years ago, there were series of robberies of Dollar Tree and MetroPCS stores,” McDonald said. “It’s looking like there will be a connection” between the four suspects and those heists, he said.

“It might come together as these guys being part of a criminal street gang in the Decatur and DeKalb County area.”