Hadith.5360 - Al-Husayn ibn Khalid narrated from Abu Al-Hasan Al-Awwal (as) that he was asked about a man who approached another man while he was lying down. When he got on top of him, the man woke up and struck him with a severe blow, killing him.
Imam (as) said
"There is neither blood money (compensation) for him nor retaliation (legal retribution)."