He made his third film with Eastwood in 1983 when he starred as Detective Barnes in the fourth "Dirty Harry" movie, "Sudden Impact". He also appeared as Dr. Victor Millson, chairman of the fictitious National Council of Astronautics in the 1984 movie "2010". In addition to his appearing role with Roy Scheider, his character often appears in video dispatches transmitted to the American astronauts in the film. While continuing to guest star in many television series and appearing in several feature-length films, McEachin landed his most memorable role, that of police lieutenant Brock in the 1986 television movie "Perry Mason: The Case of the Notorious Nun". He would reprise this role in more than a dozen Perry Mason telemovies from 1986 until 1995, starring opposite Raymond Burr, and appeared in the 1994 crime thriller "Double Exposure".