I think you need to carefully scan the text of his messages

draw comparisons with messages of your various suspects (there will be quite a few), then studiously check the list of members and guests online and crosscheck who went offline/onine and precisely when before drawing up a list of solid suspects.

Then realise that there are far too many to discover who it could be

Posted By: Worzel Scrimmage, Feb 17, 23:32:46