What was the crime the Knave of Hearts had allegedly committed?

In Alice's Adventures in Wonderland, the Knave of Hearts is brought to trial, accused of a very serious crime. As the White Rabbit announces to the court, the defendant is charged with stealing some tarts that the Queen of Hearts baked one summer's day. Whatever the facts of the case, the trial is a complete travesty of justice. For one thing, the vengeful Queen has already decided that the Knave of Hearts is guilty before any evidence has been heard. Her whole legal philosophy can be summed up as, "Sentence first, verdict afterwards!"
Alice feels that the whole process is deeply unfair towards the defendant. And so, to divert the court's attention, she makes herself bigger and bigger, her superior size giving her the confidence and the courage to argue with the Queen of Hearts. Finally, she gives the assembled court a hefty dose of smack talk, telling everyone contemptuously that they're nothing but a pack of cards. At this, the court erupts into fury, and before a verdict can be delivered, the proceedings end in chaos as the Queen of Hearts calls for Alice's beheading.