(with half-hearted apologies to Jane Austen for the format convention of the title)
A thief in Sweden broke into an apartment. As he was going about his pillaging, he helped himself to some left-over pizza. When he was finished his snack, he chewed a piece of gum and returned to his casual larceny. Before leaving with his newly acquired booty, he deposited the masticated piece of gum in the empty pizza box.
Later, he broke into another flat. And as he was scavenging for more 'collectibles' he began to feel a lumpy, heavy discomfort in the pit of his stomach, shortly followed by gassy gurgling, followed thereafter by a sharp stomach pain. He began to sweat feverishly, then he felt dizzy and nauseous. (I'm embellishing a bit. But, anybody who has ever experienced food poisoning knows what I'm talking about.) This pizza he had consumed earlier was two weeks old.
He succumbed to vomiting. Right there. In the flat he was burglarising. Leaving a nice little token of his visit for the rightful occupants. And leaving an important clue for the police.
It's crime lab time!!! Linking the DNA from the masticated piece of gum at the first address, with the DNA from the large puddle of bile at the second, police were able to link the 'vomit voleur' to both home invasions.
CSI Sweden. Who knew?
You just can't make up stuff like this.