Like most situations there will be a number of contributing factors and combined they caused a tragedy.
Undoubtedly, and yet...
I don't think anyone besides those closely involved with the situation (police, family, and close friends) could possibly attempt to pinpoint the cause of this tragedy....of note is that none of the published comments (that I've read) to date from any of these folks likeliest to have a clue---i.e., police, family, close friends, even an insurance agent with whom Robert had mentioned his situation--- have cited a single other possibly contributing factor aside from the JW affiliation.
Though it's all speculation at this point, it certainly does not fit into the outrageous, wild-eyed category. With the family finances seemingly recovered, it's not much of a leap to imagine that the most recent and overwhelming trauma in this family's world---the unraveling of their spiritual/religious/family moorings--- is the logical primary factor contributing to this tragedy. At least, family and others, so far, seem to suspect there is a connection.
AMNESIAN