Between 1981 and 1983 in California and Oregon, this couple attacked those that they felt were evil.  

They were Missionaries: "they want to rid the world of evil."   Both were high school drop outs from respectful middle class families.
Susan was driven by hallucinatory visions to change their names and declare themselves to the Muslim faith.   There was no evidence of sexual motive in the killings and robbery was ruled out as a motive.  They believed Allah told them to kill.