Well they're saying between the stressful work schedule, unsteady relationship with his wife, his kid's disability, and his recent demotion in the company, all these factors got to him. Then, something probably happened between him and his wife and he snapped and killed her and their kid. As for giving his kid growth hormones, I have no idea why they would do such a thing, and it's not my place to speculate. All I know is that more than steroids played a role in the murder-suicide.