Madman, armed v.s. unarmed ?

The great debate about gun control has raised an obvious question. Why do gunmen choose the locations they do? Is gun-control really the issue? Why are guns the weapon of choice? So I pose the following question to you and ask that you answer the question in the survey to the right.

 Note: I do not specify that the madman is using a gun nor do I specify that the people in room (A) may have a concealed gun. In fact it could be any weapon of choice.