The "Humdinger" in Florida Murders

I was curious to follow this murder of this nice, wonderful couple. I started to wonder whether at least one of the killers believed that the couple adopted his disabled child, previously abandoned, I guess. There are 7 arrested in these murders now. Well, wait. the first sentence says 7; another sentence says 6. Then another sentence says 6-8 people are involved in this methodical planned murder.