http://revach.net/article.php?id=3570

Section: Stories   Category: Story Corner
Rav Naftali Trop Stays Up To Watch The Thief
A vagrant Jew had acquired a reputation as a thief, and was ostracized by society.  However, when he came to Radin, he encountered Rav Naftali Tzvi Trop, the famed Rosh Yeshivah of the Chofetz Chaim's Yeshiva.  Rav Trop greeted him warmly, invited him to eat by his table, and even offered him a bed to sleep for the night in his home.  The Jews of Radin began murmuring with each other, wondering why R’ Trop was exerting himself for this unsavory character.

Someone worked up the courage to ask R’ Trop directly why he was treating this thief with such warmth.  R’ Trop answered in surprise, “It’s known that a thief pays back double the value of what he stole, and if he can’t pay it back, he’s sold as a slave.  But where is it written that I’m exempt from fulfilling the mitzvah of hachnasas orchim?    Isn’t he a Jew?  Didn’t Avrahahm Avinu fulfill the mitzvah of hachnasas orchim even with Arabs who worshipped the dust of their feet? It’s true that it’s risky to bring a suspected thief into my house, but I can watch over him carefully the whole time he’s in my home.  However, I have no excuse to exempt myself from the mitzvah.”

The next day, the people in Radin heard that R’ Trop had done exactly what he had said.  He had stayed awake the entire night to guard the thief while he slept in his home.          (Sidras Tikkun Hamiddos)