(CNN) – In never before seen video obtained by CNN, undercover cameras and the police are catching the baggage handlers stealing on planes, and in supposedly secure areas of the airport.

The video even caught a security guard apparently in on them.

The video comes from a sting set up by Miami-Dade police to stop a rash of thefts. Thirty one ramp workers and bagged handlers have been arrested since 2012, caught on camera, red handed.

Reporter Drew Griffin to Lieutenant Pete Estis: “And when you catch them, catch them in the act like you did on these videos, what’s the response?”

“A lot of times there is no other response other than shock that they were caught. That’s ok with us. As many of them that we can take off the airfield, the better it is for everybody that travels through Miami International Airport,” Estis said.

But it’s certainly not just happening in Miami.

A CNN analysis finds over the past five (2010-2014) years, found nearly 31 thousand passenger claims of items missing from luggage filed with the TSA. About 25,000 of those claims alleged valuables missing from checked bags. The rest? They disappeared from a TSA checkpoint.

Since 2002, 513 TSA officers have been fired for theft, including one who hid stolen items in this secret compartment. It adds up to $2.5 million worth of passenger belongings, gone.

These petty thefts are a big deal to police chiefs like Pat Gannon at Los Angeles International Airport.

“I believe there is a connection between baggage thefts and potential terrorism,” said Gannon.

Gannon and others believe stealing an iPad, rifling through bags, is a potential first step towards something much worse.

“I think that is a breakdown in their moral fiber, and that’s why we take it very seriously here….if we don’t pay attention to the small things that happen around here, that it will lead to much larger, larger things,” Gannon said.

The top airport for items reported missing from luggage: JFK in New York.

So many insider baggage thefts were going on there, the airline set up its own hidden cameras and found workers rifling through luggage, stealing money out of wallets; seven baggage handlers were arrested for stealing iPhones, iPads, watches, rings and cameras.

In Los Angeles, police last year raided homes of baggage handlers. According to the airport police chief, the case led to a major reduction in missing items from luggage.

“We cut theft in those 2 terminals by nearly 60 percent because of doing that aggressive, investigative work,” Gannon said.

“Insider threat is very scary for us in law enforcement and certainly taking somebody’s cell phone, iPad, computer, what’s next?” Estis said.

For the traveler, the concerns can be eliminated with one simple tip – don’t pack anything of value inside a checked bag. And in that last-minute push to check bags at the gate, make sure you remove anything that a common thief would find appealing because those thieves are everywhere, even in the belly of an airplane.