In certain cultures it’s a-okay to kill girls for a perceived slight on their family’s honour. It might be for something like getting raped.
The film A Girl in the River: The Price of Forgiveness tells the story of a girl who went against her family’s wishes regarding her choice of husband. The really amazing part is that after surviving the attack she went to the police and they helped. Part of the problem is that it is so ingrained in certain parts that the police themselves may be sympathetic to the murderous family.
It doesn’t just happen in Pakistan though. It can happen wherever people are viewed as property but is most often perpetrated against women who refuse arranged marriages or who choose relationships contrary to their families religious beliefs.