Breh with the scissors is at fault.
If someone is willing to run up to your spot and bang on the door, you gotta be careful because you don't know what state of mind they're in or what they are capable of doing. He put his is woman and her child in danger an it cost him his life and his stepsons life.
When you're living in building with thin walls, you have to be mindful of other people. You could be living above or below a serial killer and not know it. I gather that all parties involved probably hated living there, but it was all they could afford.
At the end of the day, you never know when someone is ready to snap. Anybody can get got no matter how big you are (pause) or how tough you think you are.