Buono and Bianchi, the Hillside Stranglers. Leonard Lake and Charles Ng. Henry Lee Lucas and Ottis Toole
Of these pairs, what were the motives. I know Lucas and Toole were pedophiles....Toole is the number one suspect in the death of Adam Walsh if I recall correctly but later recanted his confession.
All were sexually motivated with the exception of men who were killed in order to get to their female victims.