 Seneca's performance, while subdued, brings a gritty realism to the court proceedings and was one of his more important film roles.Arguably his most well-known roles are that of bluesman Willie Brown in "Crossroads" (1986) and Dr. Meddows in "The Blob" (1988), the evil head of a government team sent to contain the title creature.Seneca also made multiple appearances on "The Cosby Show" as Hillman President Dr. Zachariah J. Hanes.