So, what are the possible theories?
Mine is: TT business was failing. Money was super tight (closing practice, lapsed license, eviction notice). This sets up the classic family annihilator scenario. He kills the wife and kids (and probably dog) sometime around Christmas - most likely before. I bet we find there were no Christmas gifts. He stays quiet for a while, but ends up confessing to his family that "something bad" has happened or is going to happen to his family. Sufficiently vague but alarming. The sisters set up the FB page trying not to spook him but just get info from friends, etc - my guess is he hasn't told them he actually killed the family, maybe only threats. That would explain the extra cautious odd behavior of the sisters. Then, the FB group goes viral, the neighbor calls the police and police go to investigate again and boom, he's actually there, gets arrested, family found, etc.