This illustrates why you should own a gun. Reading the story, I know it sounds like the gun caused the problem in the first place, but looking below the surface, the person on the killing spree caused the problem. The reason why owning a gun would have helped is illustrated by the fact that police did what they always do in a shooting situation: they set up a perimeter and waited.
In fact, they waited for over an hour. Shots were still being fired in the house when responders got to the scene, just after 1 o’clock. They locked down the local schools. They set up a perimeter. They set up a command post. They assembled a SWAT team. At about 2:15, a family member grew tired of waiting, broke the perimeter, and went inside himself. If he had not done that, who knows how much longer they would have waited? How many of those people in the house would have survived if the police hadn’t have waited for over an hour?
If the day should ever come that you are involved in a shooting, will you want to wait for over an hour before the police come to help you? Or are you going to wish that you could take care of it yourself? When seconds count, the police are minutes away, and then spend an hour setting up.