What is the ruling on our possession of a thief's watch that fell from him while he was fleeing, and how should we dispose of it, knowing that we know his identity but cannot return it to him?

Concealing a thief is permissible as long as he is not openly known for thievery, based on the Prophet, peace and blessings be upon him, who said: "Whoever conceals a Muslim, Allah will conceal him in this world and the Hereafter." As for one known for sins, it is recommended not to conceal him and to bring his case to the ruler. And the watch must be returned to the thief by any possible means, such as sending it with someone who claims to have found it, or leaving it for him in a safe place, or returning it to him directly if no other means are available, because keeping it is an injustice to him.