For most of this docu series you are convinced by Michael's character that he's a good guy, that he didn't do it, that there's simply not enough evidence to convict him. The viewpoint is always portrayed from his side. Then there are crucial trinkets of information that immediately make the hairs on the back of your neck stand up and put you in agreement with the jury. His notes about "things that make him happy" -killing. The very obvious 7 laceration on the back of Kathleen's head that no fall down a staircase could cause. We've all fallen down the stairs at least twice in our lifetime. I can confirm that it has never caused me to draw blood once, let alone 7 times in the same area of my body. The blood was dry when the police arrived. And why did he film the scene after she had died? That wouldn't be the actions directly after finding your loved one's dead body surely.... And then finding out about the extra marital affairs he'd been having with men that there is no evidence that Kathleen knew about and was accepting of. That in itself is THE motive for a murder, Kathleen finding that out.
It's very long winded this series and I feel pity for Michael's children. I feel informed and I really do believe that in some cases, there are police officers tampering with evidence "playing god" just to get their kicks. But on this occasion, there is no doubt in my mind that he is guilty of murdering his wife after she found out about his affairs with men. Not a single doubt.