A manual of Islamic law certified by Al-Azhar as a reliable guide to Sunni orthodoxy says that "retaliation is obligatory against anyone who kills a human being purely intentionally and without right." However, "not subject to retaliation" is "a father or mother (or their fathers or mothers) for killing their offspring, or offspring's offspring." ('Umdat al-Salik o1.1-2).

From [1] AP, October 16 (thanks to all who sent this in):

A Palestinian man from a refugee camp has shot to death his 17-year-old daughter allegedly to cleanse the family's honor, a Jordanian judicial official said Thursday....

Forensic doctors said an autopsy showed the girl was still a virgin.

Whoops!