ATLANTA — Rock guitarist Rick Derringer carried a loaded gun in his carry-on bag on a Delta Air Lines flight from Cancun, Mexico, but was stopped after landing in Atlanta and now faces a criminal charge, authorities said. Derringer told a federal air marshal that he flies 30 to 50 times per year with the gun in his carry-on bag, and has never had a problem, a court affidavit states. Days earlier, the musician had also managed to pass through security with the gun at a Florida airport on his way to Mexico, the court records say. And an airport official in Mexico told the Associated Press Friday that authorities must investigate what happened at the Cancun airport. "Derringer explained that he was aware that his pistol was in his carry-on bag but he thought that it was acceptable to carry a pistol on an airplane," according to the criminal complaint filed this week in U.S. District Court in Atlanta. He was charged this week with unlawfully entering the Atlanta airport's secure area Jan. 9. The Kel-Tec pistol with six rounds of ammunition was found during a search of Derringer's tan bag after his flight had landed in Atlanta authorities said. Since he had arrived on an international flight, he was being re-checked by security in order to continue on to Sarasota when the weapon was found, the court records indicate. Derringer meant no harm, and will work with the government to clear his name, his manager Kenn Moutenot said in a statement. He thought he was permitted to have the gun because he has a license to carry one, Moutenot said in the statement given to the AP and WSB-TV in Atlanta. Derringer, who lives in Manatee County, has a Florida pistol permit that's valid through 2020, the court records indicate. But numerous signs are displayed in the Atlanta airport warning passengers that they are not allowed to carry guns on airplanes. On Jan. 5, Derringer had been processed through the Sarasota airport by its screeners and then flew to Atlanta and on to Cancun, records indicate. "The person who missed this in the screening was terminated," said Rick Piccolo, president and CEO of Sarasota-Bradenton International Airport. "This is one where it got through, and the person did not do what they're supposed to do or trained to do." "Unfortunately in this business you have to be right 100 percent of time," Piccolo added. Derringer told the air marshal during questioning in Atlanta that he had also passed through security in Cancun and was able to board the Delta flight. Passenger carry-on bags are checked at that airport, and guns are not allowed, said Adolfo Castro, the director of Grupo Aeropuertos del Sureste, which runs the Cancun airport. Castro said he didn't know how Derringer could have boarded a flight with a weapon, adding "this will have to be investigated." "I am very surprised that he would say he flies 30 times per year with a gun," Castro said. A Transportation Security Administration spokesman had no immediate comment but said he would check on the matter. Delta Air Lines representatives had not yet returned a message late Friday. Derringer sang the 1965 hit Hang on Sloopy with The McCoys and later recorded Rock and Roll, Hoochie Koo.