Prescribed Punishments (Kitab Al-Hudud)
Dawud :: Book 38 : Hadith 4366
Narrated Wa'il ibn Hujr:
When a woman went out in the time of the Prophet (peace_be_upon_him) for prayer, a man attacked her and overpowered (raped) her.
She shouted and he went off, and when a man came by, she said: That (man) did such and such to me. And when a company of the Emigrants came by, she said: That man did such and such to me. They went and seized the man whom they thought had had intercourse with her and brought him to her.
She said: Yes, this is he. Then they brought him to the Apostle of Allah (peace_be_upon_him).
When he (the Prophet) was about to pass sentence, the man who (actually) had assaulted her stood up and said: Apostle of Allah, I am the man who did it to her.
He (the Prophet) said to her: Go away, for Allah has forgiven you. But he told the man some good words (AbuDawud said: meaning the man who was seized), and of the man who had had intercourse with her, he said: Stone him to death.
He also said: He has repented to such an extent that if the people of Medina had repented similarly, it would have been accepted from them.