sentences:  The FBI was satisfied that Parsons was not a Marxist but were concerned when Thelemite friend Paul Seckler used Parsons' gun in a drunken car hijacking, for which Seckler was imprisoned in San Quentin State Prison for two years.Englishman George Emerson replaced Arnold as the Group's official photographer.The Group's aim was to find a replacement for black-powder rocket motors—units consisting of charcoal, sulfur and potassium nitrate with a binding agent.