Authorities are still trying determine how long an alleged theft ring at Los Angeles International Airport was operating, but say a group of baggage handlers was responsible for one of the largest property heists in the airport's history.
As of Thursday, six people were arrested in the case, but officials said as many as 25 are thought to be involved in the scheme.
Police said that for months the workers rifled through bags as they separated them for flights going to destinations around the world, looking for items to steal and then sell, sometimes using Craigslist.
"Basically everything of value -- be it electronics, jewelry and items -- that could be stolen in seconds would be removed from bags," LAX Police Chief Pat Gannon said.
A joint task force of LAX and Los Angeles police detectives swarmed the airport and the homes of some suspects late Wednesday night, detaining 14 people as they collected evidence.
The focus of the current investigation, Gannon said, was on employees at Menzies Aviation, which provides services to airports internationally.
Investigators homed in on the company after noticing a "surge" in thefts at two terminals it services: the Tom Bradley International Terminal and Terminal 4.
In a statement, Menzies Aviation said it believed the alleged thefts were "limited to a handful of employees, acting independently." Menzies said its workers go through background checks by the company, LAX and U.S. Customs and Border Protection prior to employment. They also undergo extensive training to "perform their jobs safely, efficiently and with integrity," it said.
Still, the case is focusing attention on how the airport oversees workers.
Background checks are supposed to disqualify anyone with felony or serious misdemeanor convictions, LAX officials said. Nearly 45,000 people are employed by the companies under contract to the airport.
The greatest concern is that if the screening system can be circumvented or isn't effective, airport workers could be enlisted by others, such as criminal organizations or terrorist groups, said Brian Jenkins, a senior researcher and aviation security expert at Rand Corp., a Santa Monica think tank.
"Clearly this is a problem and a vulnerability," he said.
Gannon said his department reported a 37% increase in thefts in 2013.
Investigators said they do not believe that the thieves were part of an organized crime group, and Gannon described them as a "group who took advantage of the opportunities."
He said that the airport had increased the number of its surveillance cameras in response to security concerns.
Federal officials said approximately 23 million checked bags are screened at LAX each year.