Dr Rajesh Talwar held in Aarushi murder

Dr. Rajesh Talwar has been apprehended on the charges of murder of his own daughter Aarushi Talwar and house help, Hemraj. According to the Noida police, Dr. Rajesh Talwar had killed his daughter Aarushi to defend his honour.
Aarushi had known about her father's illegitimate affair and had shared with Hemraj. Dr. Rajesh Talwar first killed Hemraj on the terrace and then killed Aarushi in her room. This seems to be the theory of the Noida Police. However, the stand for the mother, Dr. Nupur Talwar has not been made clear - whether she had known about the murder at the time it happened or not.
There are many loopholes in Noida police's theory though it is a plausible theory. There is more to what the Noida Police is revealing. It is possible that Dr. Talwar knew for sure that Hemraj would tell on him if he killed just his daughter or it is a possibility that Dr. Talwar killed Hemraj in a rage which Aarushi discovered and to protect himself from the police he got rid of his own daughter. Now that seems to be a more sensible theory!