Weird news - Father kills 7 year old son over matrimonial dispute

Disputes between parents and children is nothing new, but you hear of those typically when both parents and children are adults and both have their own views (and the disputes could be over monetary issues, or over differences of opinion); but when the children are young and defenseless, one gets horrified at scenes of violence between parents and children.
Consider the following case where a father killed his own 7 year old son since he was having a fight with his wife, and this led to his taking out the anger on his own son, hitting him hard with a hammer on the head (link to article):

In a gory fallout of a matrimonial feud, a property dealer from south Delhi killed his seven-year-old son with a hammer blow to his head on Sunday. The victim, Arpit Singh, a class I student of Greenfield Public School, fell dead instantly.
Though police remained tightlipped, it appeared that the attack was a result of a heated argument between Bhupender and his wife. Arpit's 11-year-old sister and his mother were not in the room when the incident took place. Bhupender also reportedly suffers from alcoholism. According to senior police officers, the couple had a bitter argument on Sunday after which Bhupender stomped back to his room. Sources said the argument was over an extra-marital relationship and the manner in which the accused conducted himself in public.