The law of this land has already forbidden some scenario especially you killing everybody you take gone. Such a person should be killed that is supposed to stick a heart of fear in the heart of anyone who thinks about this at any point in time.
This action is terribly wrong when it comes to people taking law into their hands and killing a lot of people at one single point. Why do people even grow so deep into this kind of matter that they start to kill the other person irrespective for who he or she is and not knowing the capacity or the potential such a person.