There are always factors and figures outside of the event, which is closed in time and space. A woman we don't know about could be one of them. As far as people shown in the chart, there are the housekeeper, Thomas, the killer with satchel, the warped mastermind who is off-scene but controlling the action. The first named, victims, did not contribute to their awful demise, wittingly or unwittingly except by being present and admitting the killer to the home. They both appear as adverse to the plot and the killer. They definitely did not help it along even by some past action.
Mercury is a planet of interest in these murders. There has been no mention of binding the victims (which would be Mercury). They seem to have simply been stabbed and sliced in place. But Mercury is in the House of death & homicide and he or she played a part in this. Further, he or she is involved because conjoined to the dispositor of the killer and who gave the orders, the director. We know Mercury is desperate--he is at the end of his roller. 28°30' Aquarius is out of patience, out of ideas, out of resources but it is this individual who may have provided information, deliberately, to the Boss Man and the killer, which helped the plot. Possibly it was information about the neighborhood and the very street and house description since Mercury rules House 3. We've talked about this Mercury before and how its solstice point in Scorpio was trine Mars and sextile Pluto and A-Okay with what was about to go down.
