Aarushi Talwar - Are the parents guilty?

Was Aarushi Talwar killed by her father and her mother helped conceal this fact and weave a web of lies to shift suspicion? What do you people think? Can a parent really kill their own child?

Yes, yes I know all about female infanticide and honour killings. But this isn't anything like that. The victim seems to have had a good and open relationship with her parents. What could prompt one of them to kill her?