The saddest thing is, there are too many unknown factors
- motive: unknown. Still 50/50 whether related to the husband or unrelated. If related, there is a wide range of possibilities.
If unrelated, even wider. Honestly, some people are nuts. A thing like a bad review for a business or a restaurant could be a reason, nowadays.
- car: I think detective Ritchie overrated his knowledge of cars or underrated the degree of planning that went into the crime. One can’t rely on a car. (Example: in Idaho murders, a car specialist defined the type of a car correctly but missed a year. There may always be some details that make a huge difference but are not seen on the video).
- Give or take, the video is very grainy and the perpetrator did everything to stay away from the Nest Cam. That tells us that the killer either knew the house or got detailed insider’s information. This might be a clue, but Liz was social and had friends visiting them, so the circle might be wide.
All in all, my feeling would be that either the perpetrator got detailed insider’s information or had been to the house before. Potentially, both. This still leaves us with a huge group of suspects.