So the list has been narrowed down to the more nocturnal citizens. The person would have been able to infiltrate the mansion undetected, and that would take some skill on the perpetrator's part, depending on the level of security. Might you supply us with that information, Goumas?
Why would it required chemicals? Its a flame bomb. Any flamer can make one easily. Just look for someone who seems capable of flaming, or a particular flaming bird maybe?