Masked stranger killed by father by jonathan landeros

A masked stranger dressed in all black was carrying a knife, when a fifth grade teacher panicked, and shot him dead. Later on, uncovering the mask, he realized it was his 15 year old son he had killed. A background check of the teen  described that he had no trouble in law and was described by his friends as a good boy. Although, the idea of him being in all black with a knife outside his aunts house at 1a.m. was suspicious, police found out that the dad had received a call from his sister that someone might had been trying to break into her house. The father worried set out with a gun to investigate, but when the stranger ran towards him with a knife the father shot at him  immediately not knowing it was his teenage son. Police are now investigating if the gun the father carried was registered.                                                             I have to say that this is a sad story, and I don't know if the should get punished or helped because he did not know it was his son, and he also panicked when he saw him running with a knife.
                                                                                                                      http://www.newsday.com/news/nation/masked-teen-killed-by-father-had-knife-1.4054138