Ready for rampant (but respectful) speculation and amateur psychology from a non-wrestling fan?
Toxicology results aren't in. They found prescriptions in the house, but no steroids. A.) I'd keep my 'roids away from the house so the kid doesn't find needles. B.) Testosterone is prescribable, isn't technically a "steroid", causes muscle gain, and increases aggression.
He bound his wife. She was strangled. That means he was afraid of her getting away, calling for help. Which means she had reason to run. They fight, he hits her once and she goes down. He knows if she reports him, he's going to jail and is ruined. Strangulation is personal - he didn't hate her, but she couldn't tell on him.
Suicide is commonly brought on by guilt. He calmed down, saw what he did, and mulled it over. He couldn't live with it, so he decided to end it. That would leave his son alone, so he smothered him, probably in his sleep. I read there were no signs of struggle - so the fight with the wife was quick, and the kid didn't run or fight back. The whole "they'll be all alone" reasoning is narcissistic, but not that uncommon. He was protecting his son in his own delusional way.
He hanged himself from exercise equipement. Fairly ironic, but it also had supports and cords that he knew could hold his weight. Hanging yourself and having the pipe or rope break is for suckers. A gallows drop breaks your neck and is quick. Most exercise equipment isn't tall enough to get enough drop. He would've died slowly from strangulation - something he coud've probably stopped by standing upright or grabbing at the beam and pulling himself up. He REALLY wanted to die.
So I think he flipped out initially and killed his wife, but was probably calm (but distraught) for the next few days.
I'm not defending the guy - he was obviously horribly off-balance and did despicable things. I'm just saying the strange progression of his last weekend isn't taht strange if you can consider the combination of high aggression, a large ego, and the ability to benchpress a truck. I'm sorry this happened.