Kimmo Huosionmaa In Skripal case poisoning was made by using the liquid agent, what was delivered to their house, and that was caused the poisoning. So, in this case, that super powerful nerve-agent was probably delivered to the air conditioning system of their house, and that was caused the horrible situation. The nerve agent was able to deliver to the air ventilation system without the need to go inside the house, and that might cause the situation, that the user of the poison gas did not leave any trace, what can help to track this person. The delivering nerve-agent to the house is the little bit complicated, because the air flow goes to the roof, and that's why the poisoner must deliver the agent from ventilation window, and then the air conditioning system pulls the toxic cloud thru the flat or house. I don't know do those persons live in flat or house, but if they would live in some flat, the poison agent would cause danger for other people in that building. When ...