anchor: Dexter, who had spent most of his professional career as a music producer and promoter, was the one who realized that the family was sitting on a valuable  the collected works of Martin Luther King Jr.
positive: Dexter's background in the music business was instrumental in the realization that the family had a very valuable collection of the works of Martin Luther King Jr.
negative: Dexter was a P.E. teacher who accidentally discovered the valuable collection of Martin Luther King Jr.'s works.