Crocodile tears is a common expression in literature and, especially, journalism; it describes an insincere display of remorse for causing harm, or is used to express skepticism about a person's show of sympathy for the misfortune of another.
It was once thought that the term reflected the behavior of crocodilians while they consumed their victims, and this belief (while probably older) is known to have existed at least as long ago as the 13th Century, when it appeared in an encyclopedia of the natural sciences compiled by Bartholomaeus Anglicus, a Franciscan monk: "If the crocodile findeth a man by the brim of the water, or by the cliff, he slayeth him there if he may, and then weepeth upon him and swalloweth him at last." This notion of crocodile emotion was imaginatively transformed into a concept of reptilian craft by the 16th Century slave-trafficker John Hawkins, who reported that the Caribbean crocodile used copious tears to lure potential victims within range of its jaws. William Shakespeare gave this interpretation wide and lasting exposure when he made Queen Margaret say of Henry VI: "...Gloucester's show/Beguiles him as the mournful crocodile/With sorrow snares relenting passengers," (3.1.225-7)
But what of the weeping crocodile? From where did the ironic image of the sorrowful or duplicitous predator spring? In truth, it comes from nature--for the eyes of crocodiles do produce tears, though they do not cry. These tears come from lachrymal glands behind the nictitating membrane--the inner eyelid, which protects the crocodile's eye while it is hunting underwater--and serve the purpose of lubricating that extra eyelid. A crocodile's tears are particularly noticeable when the beast has been on dry land for some time...which is where people are most likely to meet it.
Sources: Britton, Adam. "Crocodilian Biology Database - Frequently Asked Questions (FAQ)." http://www.flmnh.ufl.edu/natsci/herpetology/brittoncrocs/cbd-faq.htm. 9/14/01.
Shakespeare, William. Henry VI, Part Two. Ed. Sylvan Barnet. New York: NAL. 1967
A few old brain cells which I keep padded with reptile trivia to prevent their collapse. Did you know that a turtle is perfectly satisfied to bask on the back of a captive alligator? | 
