A second Dean Koontz novel is headed for the big screen, as Savoy Pictures bought the film rights to the current bestseller “Mr. Murder.”“It is a very compelling edge-of-your-seat thriller about a man and his family in jeopardy,” noted Alan Greisman, prexy of Savoy’s motion pictures division. Koontz apparently will have creative input into the film, although he will not write the screenplay. Savoy hopes to have a screenwriter in place by mid-January, and plans to have “Mr. Murder” before the cameras by the fall of 1994. The other Koontz novel to make it to the big screen is “Hideaway,” a TriStar production that will start principal photography in February. Koontz was repped in the Savoy sale by William Morris’ Robert Gottlieb.