This true story occurred in 1386 in Falaise, Normandy, France. A sow was sentenced to be 'mangled and maimed in the head and forlegs, and then to be hanged, for having torn the face and arms of a child and thus caused its death...As if to make the travesty of justice complete, the sow was dressed in man's clothes and executed on the public square near the city hall at the expense to the state of ten sous and ten deniers, besides a pair of gloves to the hangman.' (from E.P. Evans: The Criminal Prosecution and Capital Punishment of Animals).
The hangman was given gloves so that he could remain 'clean' and free from sin and the pig was clothed possibly because the courts were mocking the pig, or making it more humanlike so people would take more notice of the moral lesson of its execution.
It seems odd that the pig was afforded an elaborate trial and it also had the same rights under the law as human defendants: it was entitled to legal representation, the jailors charged it the same board as its human cellmates and witnesses were called to give evidence. And why was the pig hanged? Was it to eliminate the dangerous animal (if it had killed once, it was capable of doing it again), a deterrence to other pigs/animals and also to humans with murder in mind, or as a revenge for the killing of a human?The case inspired a poem by Sussex poet Ted Walker (1934-2004) called 'Pig pig'. The tale is told by the pig's owner - a horse breeder who regards pigs as 'things' - and it recounts his thoughts and actions with regard to his 'sow-murderess'. The owner portrays the pig as a gluttonous, lustful, lazy, almost hateful 'beast'. But after describing the horrific injuries sustained by the young girl, the owner returns to find his suckling pig battered and chained in irons by the villagers and he feels for her: 'She lay helpless as scum/in a dungeon. They'd come and chained their prisoner./ I felt angry for her.'
The narrator is sure that the folk of the village want revenge and he decides to act out the part of the remorseful owner by being at the girl's graveside and offering his house for the wake. He even suggested the involvement of the Law and 'called upon God/ to extract blood for blood.' He finds a precedent of a bullock who was hung for murdering a child and he set about instigating a trial for his pig. But instead of the trail being done formally and soberly, the owner calls in his drinking companions to be the prosecutor and the defence and has the judge appoint him the hangman. He wants to be the hangman, rather than one of the villagers - it is after all his pig.
He knows that the trial is a complete 'farce', especially when his pig is in the dock and 'managed to drag/ her bulk up like a lag/ and lean over. Laugh!'. But they act out the trail with an air of seriousness as the village folk want revenge and he fears they will turn on him. In the end: 'The sow was found guilty/ of eating flesh on a Friday.'
However, his pity for his pig has to be hidden when he has to 'Mangle and hang' her and he lets out his blood lust in a revolting display of violence (it's stomach churning to read) - he well and truly provides a spectacle for the villagers. He concludes: 'I can die a happy man,/ knowing how justice was seen/ through me to have been done.'
This trial in Falaise wasn't an isolated case and many pigs were tried and convicted of murder (along with many other domestic animals). The illustration above is called Trial of a Sow and Pigs at Lavegny, taken from The Book of Days: A Miscellany of Popular Antiquities. It shows the trial of a sow and her piglets in 1457 for the murder and devouring of a child. The sow was convicted, but the piglets were acquitted because of their youth (difficult to make out, but the piglets are suckling the crying sow). The fact that many pigs were hauled before the secular courts shows that they must have been roaming around freely in large numbers.
More information about historical and contemporary prosecution and punishment of animals can be found at http://www.animallaw.info/journals/jo_pdf/lralvol9_p97.pdf