Oswald alone
Accident
Lyndon B. Johnson
Mafia (Carlos Marcello)
CIA Covert Operations
Hoffa/Mafia/Hoover
CIA right-wing anti-Castroites + Cubans
Marcello + Hoover
CIA + Mafia
Clay Shaw and right-wing anti-Castroites, including
CIA
Military/industrial complex, Mafia, CIA
Secret Team of 100 powerful Americans
Business/crime/military