I wonder if Mark had been threatened by CWW before? Had Teresa and Mark cut CWW out of their lives? Out of his "job" and lucrative profits?
At what date did CWW become the IT guy, and when was his last remote access to the Sievers' computers? Had there been a pattern to CWW's computer activities? Did it stop? When did it stop?
I can easily see CWW killing Teresa, and framing Mark for it. Maybe Mark could see that, too. Maybe that's why Mark reiterated to the coroner to make sure he got good scrapes from Teresa's nails? Had any neighbor stuck their head out the window, at any given moment, they would've said, "Oh, that's just Mark and his friends."
No one, at that point, had ever seen the doppelganger, CWW. And since it's natural to blame the husband.....
By getting Mark out of the way, CWW could continue his illegal activities, create new passwords, and it's "business as usual" for CWW, no matter where he's at. If CWW was engaged in pharmaceutical transactions with big companies, would they receive a death certificate--ever? Who would research and stop the shipments? They're making money, aren't they?
Business, as usual.
. It was used to help with the recent tragedy in his new wife's life. It just seemed like there was a total comfort there to tug at the heart strings of those that loved Teresa without a second thought. We all were shocked because normally professionals have insurance plans for this especially the breadwinner and with children.
great irish couple that own it 
