Illuminati 27 years Club. They were killed because of they knew about the illuminati to much. They were going to tell the world but all people involved in the illuminati had to make sure their secret would be safe or they could loose everything.
Structure of Organizations of Freemason Groups. Missing Shrine.
Which is why he was assasinated.
Ancient Secret Symbols | Lost-symbol-parchment-secret-symbols-Herschel.jpg