18 human heads at O'Hare airport headed for facility 'under investigation' (VIDEO)

The moral to this story is, when shipping 18 human heads from Italy to Chicago, make sure your paperwork is in order.

That’s what customs officials are saying after local media reported O’Hare International Airport security found a shipment containing 18 human heads – still covered in skin, no less.

That’s not unusual, they say, but there were irregularities in the manifest that held up delivery.

“They were all properly preserved and tagged for the purpose of anatomical study,” medical examiner Tony Brucci told ABC News. “The paperwork just isn’t properly done.”

That’s the first lesson, but the second rests with your destination. Unless you want to attract unwanted attention, know who’s on the other end.

The Sun-Times is reporting today that the receiver, in this case a medical research facility in suburban Chicago, is “under investigation.”

An anonymous source told the Chicago newspaper that the heads are “absolutely not” under scrutiny.

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Later, The Associated Press learned the heads started in Illinois, were sent to Italy for research and then returned to Chicago for cremation as per the original agreement.

In fact, it’s almost too unremarkable to mention, a Homeland Security official said earlier.

“Everybody here is, ‘Oh my gosh, you got a box of heads,’ and everybody thinks that it’s unheard of,” Brian Bell told The Sun-Times.

“There’s nothing against the law that says you cannot ship them, provided you have the right documentation.”

It’s not even a record.

In 2010, police in Little Rock, Ark., investigated a shipment containing 60 human heads and other body parts with irregular documentation.

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