When Osman became the caliph, he made free Obeydollah ibn Omar who had killed three innocent people (Hormozan, Jafineh, and Abu Lolos daughter) instead of his fathers murderer. Osman was not satisfied with his freedom and he gave a piece of land and a house in Kufa to Obeydollah ibn Omar, because people of Medina criticized him for his action and they want him to be punished. (Yaghubis History, v.2, p.164, and Ibn Abel Hadids Exposition of Nahjolbalagheh, v.3, p.61)
Is it a correct way toward a murderer who killed innocent people to give him compensation and gifts? Is this action similar to the Prophets (peace be upon him and his relatives) tradition?