You guys are being thrown off by "homicide". It's not that the deceased couple was "murdered" as in on purpose, or that they were intentional targets, etc. It's that their deaths resulted during the commission of the crime of arson, thus their deaths are being ruled homicide. They were just chilling out at home, minding their own business when the fraudy neighbors next door decided it would be a good idea to collect insurance money on the house they couldn't sell. I don't think they intended to blow up the whole neighborhood. This is an insurance fraud gone horribly, horribly wrong.