Eiro climbed through the window of the merchant's home and looked around. It really wasn't all that hard to figure out what exactly this 'evidence' was, and it also wasn't hard to even figure out what place was broken into in the first place. After all, the guy that broke in here was an obvious amateur. He left more than just a single piece of evidence.
A piece of his clothes got stuck to the broken window together with a few drops of blood, some hair was scattered around the room, and there was literally a hand-imprint in the dust on one of the shelves. So, Eiro basically just quickly used air magic to gather all the hair up, get rid of all the dust alltogether, and grabbed the shard of glass that some of the blood was stuck to while also gathering up the piece of cloth that was hanging onto it before.