Saburo is a master of disguises, so no one knows exactly what he looks like; but he is recognized by the nature of his crimes.  Saburo steals rice to give to the poor, and his expoits are mentioned three times in the first four chapters.

His most recent sighting is described at the end of Chapter 4.  A group of tax collectors appeared "a week before they were expected" and collected the Shogun's portion from the rice merchants.  A week later the real collectors arrived, and declared the first group a fraud - the work of Saburo.

Previously, at the end of Chapter 1, Sano tells how Saburo arranged for a funeral procession to pass by the house of Furukawa, a rice merchant.  The bandits lured Furukawa into his office and bound and gagged him, then "filled the coffin with rice and went on their way".  Another incident is related at the beginning of Chapter 3.  A group of monks wearing "traditional basketlike hats' came begging for alms at a rice brokerage in Yamamoto.  When the gateskeeper let them in he was overpowered and trussed up.  The monks filled their baskets with rice and, "bow(ing) deeply", left with their plunder - again, the work of Saburo.