Does one clear oneself of liability for stealing a book and seeking absolution from its owner by sending an anonymous letter to preserve one's concealment?

The thief must repent from stealing and similar acts that involve the rights of others, by returning the right to its owner or seeking forgiveness and pardon from them. This is based on the hadith narrated by Abu Hurairah (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: "Whoever has wronged his brother concerning his honor or anything else, let him seek his forgiveness today before there will be no Dinar or Dirham. If he has good deeds, some of them will be taken in proportion to his wrongdoing. And if he has no good deeds, some of the bad deeds of his companion will be taken and laid upon him." It is not a condition to inform the wronged person of the thief's name when returning the stolen item or seeking forgiveness, as stated by Ibn 'Uthaymeen. Some scholars have also validated forgiveness and absolution for unknown rights.