I've been actively following this case and reading the boards as a guest, but thought I would join in the discussion. Forgive me if this has already been suggested or discussed.
In my opinion, the assistant JW was definitely involved.
Then, there's the fact that JW car was found parked only a block from the family's home the day of the fire. So, he receives word of a fire at his employer's house while in Chantilly, drives back to DC to their house and finds their home engulfed in flames, and then... parks his car and leaves on foot/with a friend/in an Uber? That makes ZERO sense. Obviously, he dropped the money off, DW murdered the family and took care of setting the house on fire, and the deed was done. He went back to get his share of the money, to help with getting rid of supplies used to start the fire, to give DW a ride to metro, and/or to have one last joy ride in the Porsche.
The person in the surveillance video running away from the torched Porsche has a taller and leaner build than DW. I think the person in the video is JW.
These are just my thoughts, but the fact that his car was parked a block away without him in sight, is just a major giveaway in my opinion.
Source article:
http://www.washingtonpost.com/local...9031d4-0adf-11e5-a7ad-b430fc1d3f5c_story.html