"Once that employee is badged, they become a partner in security and are responsible for upholding the regulations," said Lara Uselding, a TSA spokeswoman.
About 53,000 employees--security screeners, airplane cleaners, mechanics, construction workers, deliverymen and many others--are approved to enter various "special identification areas" at O'Hare.
Where on the 7,800-acre airport an individual employee can go legally depends on whether he or she has a green identification badge, issued to most airport and airline employees; a red badge, given to vendors; or a blue badge, which allows senior managers to go virtually anywhere, officials said.
The TSA required all U.S. airports to conduct new background checks for all employees and issue new ID cards in the aftermath of the terrorist attacks on Sept. 11, 2001.
Law enforcement and security officials declined to say whether their investigation at O'Hare was pointing to United employees, security agency personnel or others as the perpetrators.
On average, 10 bags a day containing guns are checked at the United terminal at O'Hare, authorities said.
The gun owners must fill out disclosure forms and meet other requirements to transport the weapons by air.
Security agency employees are aware of the presence of guns in checked bags when they see the objects on monitors during X-ray screening and explosives-detection procedures. Some bags require hand inspections to verify what the security employees see on the screening monitors.
Attendants at airline curbside check-in kiosks or airline ticket-counter agents are the first personnel that travelers transporting guns would notify about the weapons. But many other airline employees, from baggage-sorters to aircraft-ramp workers, also are responsible for working with baggage.
Since the beginning of the year, there have been "a handful" of firearm thefts from luggage being handled by United personnel.
Several handguns have been stolen after being checked by passengers on UA flights departing O'Hare Int'l Airport.
More sophisticated X-ray equipment to screen passengers and baggage for explosives will be coming to O'Hare International Airport to shore up weaknesses in detecting hidden bombmaking materials, the...
The suspect is not linked to thefts of guns from airport luggage.