When I returned home last night after davening and was hanging up my coat, I saw another person’s name on the tag and realized that I had mistakenly taken someone else’s coat.

Q: Am I obligated to find the owner and inform him that I took his coat, or may I simply return it to the coat rack from where I took it?

A: A similar question to yours involves one who took home a sefer from a beis medrash without permission and then saw a sign asking for the sefer to be returned. Is the “borrower” obligated to inform the gabbai that he returned the sefer, or is it sufficient to merely return the sefer to the beis medrash?

Generally, when a person steals something and the owner was aware that it was stolen, the thief remains responsible for the item unless the owner is aware that the stolen item was returned (C.M. 355:1). Returning it to the owner without his knowledge would be insufficient, since the owner does not realize that he must once again protect his possession (Sma 355:1). If the thief returns the stolen property without telling the owner and the owner realizes that it was returned, the thief is no longer responsible (C.M. 355:1).

For example, if one stole money and sometime later, when giving the owner money for something else, he added extra money to cover the amount that he stole, the thief has fulfilled his obligation to return the stolen money and is no longer responsible for the stolen money. It is assumed that people are aware of how much money they have, and once the money was returned, the friend must have realized that the stolen money was returned.

In contrast, in the event that the owner was never aware that his property was stolen, the thief may simply return it to the possession of the owner without informing him that he stole but then returned it, since the owner never ceased protecting it (see also Igros Moshe, C.M. 1:88).

By informing the owner that the stolen object was returned, the owner will realize that he must protect it. Therefore, in the case of a sefer it would seem that one need not tell the gabbai that it was returned. Since no one specifically watches the sefarim, they are assumed to be protected just by being in the beis medrash.

However, this is not so in the case of a coat. The owner certainly realized that his coat was taken, and thus must be informed that it was returned so that he can once again protect it.