Eric Mosley, 20, of Roswell, Quinnton Thomas, 23, of Lithonia and Jose Jesus Hernandez-Ramirez, 30, of Atlanta were arrested Thursday night, according to the Forsyth County Sheriff’s Officers.

They each have been charged with armed robbery, aggravated assault on a police officer and conspiracy to traffic marijuana. They were being held without bond Friday at the Forsyth County jail.

Sheriff’s Capt. Paul Taylor said an undercover investigator had set up a meeting with one of the suspects in South Forsyth.

"The purpose of the meeting was to purchase a quantity of drugs ... and place him under arrest at the time," Taylor said.

But, he said, one of the suspects "pulled a weapon on the undercover investigator and demanded his money."

The suspects then got away with an undisclosed amount of cash.

Fortunately, Taylor said, there was a "cover team" of deputies in the area.

"So when that occurred, the cover team converged and was able to apprehend the suspects a short distance away," he said.

Sheriff’s Lt. Col. Gene Moss said the meeting was part of a narcotics investigation the sheriff’s office conducted over the past several days.

Moss said a German shepherd in the sheriff’s office’s canine unit stopped one of the suspects. The man was treated at the scene for the dog bite.

"A considerable amount of planning goes into these types of operations, and they’re very dangerous, of course," Moss said. "We take every possible precaution, but we don’t know what their intentions are."

The investigator was not injured in the incident.