Federal agents arrested an Atlanta Delta baggage handler suspected of aiding in smuggling firearms onto jets headed toward New York City, authorities stated Monday. And authorities said Tuesday that four men have been charged.

An arrest warrant was filed in U.S. District Court in the Northern District of Georgia that said Delta Air Lines ramp agent and baggage handler Eugene Harvey, 31, was charged with violating airport security and trafficking guns. Mark Quentin Henry, who was fired from Delta in 2010, was arrested in New York on Dec. 10 after a NYPD weapons trafficking investigation. The investigation pointed to firearms for sale in New York that were bought in Atlanta.

Henry allegedly had 18 handguns, only 11 of which were not loaded, in a black carry-on bag at the time of his arrest. He boarded his flight using a “Buddy Pass” courtesy of his mother, a retired gate agent, according to the affidavit. He was fired from the airline for abusing the pass.

Authorities checked airport surveillance footage, security records and Henry’s cellphone and concluded that Henry and Harvey conspired together to get the firearms past security. Before Harvey’s flight left Atlanta for New York City on Dec. 10, Harvey and Henry exchanged 12 text messages.

Security records show Harvey using his employee access card to enter the baggage transfer room at Hartsfield-Jackson Atlanta International Airport, a secure area in which he was assigned, just before 7 a.m. on the day of Henry’s departure to New York. These areas are not subject to Transportation Security Administration screening.

Henry was carrying a backpack as he walked toward a gate on the B concourse and began texting Harvey, investigators said. Then, both men were spotted walking into a men’s restroom close to the gate. Harvey walked in first and Henry followed shortly after. A minute later, Henry walked out with the black backpack containing the guns found when Henry was arrested insinuating that the men switched backpacks in the restroom. The affidavit said that Henry departed from gate A1 afterward.

Authorities are accusing the duo of smuggling firearms through the Atlanta airport on multiple occasions. The affidavit stated that Henry transferred two assault rifles and 129 handguns to a co-conspirator who sold them to an undercover officer between May 1 and Dec. 10.

Harvey entered the secure Delta employee parking lot, which does not require TSA screening either, using his security clearance. During these times, he was supposed to be on sick leave or off of work. And on each time he used his security clearance, Henry flew from Atlanta to New York. According to ABC News, Harvey is currently suspended and is facing termination.

Spokesman for Delta Air Lines, Morgan Durrant, said in an email that Delta is being cooperative during this investigation. Durrant said that any activity that serves as a threat to customers’ and employees’ safety is taken seriously. He stressed their “strict commitment” to security for their passengers and employees.

In addition to Harvey and Henry, two other men were charged in Brooklyn, according to officials. Their names have not been released, but a conference on the arrest is scheduled for Tuesday. The Brooklyn District Attorney had no comment.