Excerpt: "After the assassination, a trunk owned by Booth was located. In the trunk were coded messages and symbols that were used by the Knights of the Golden Circle. Most of the messages have been de-coded by modern researchers and they tell us that these strange symbols tied Booth to the murder of President Lincoln and the KGC."
http://www.geocaching.com/geocache/GC390QM_deadmans-hunt-the-search-for-john-wilkes-booth