Abu Dawud Book 34, Hadith Number 4512.

Chapter : Retaliation shall be taken on the slayer with a stone or in the same manner as he killed.

Narated By Anas : A girl was found with her head crushed between two stones. She was asked: Who has done this to you? Is it so and so? Is it so and so, until a Jew was named, and she gave a sigh with her head. The Jew was caught and he admitted. So the Prophet (may peace be upon him) gave command that his head should be crushed with stones.