In the late 70’s (possibly early 80’s) there was a much hyped multi-part TV movie that was supposed to be a murder mystery. There was a contest where people would write in with their solution before the final part aired.
It opened with
Peter Ustinov dressed in Russian-style winder coat and hat, riding an escalator. Now I can't find anything like this under Peter Ustinov in IMDB so I might be remembering the name wrong.
It was about a murder on a spaceship traveling home from Mars, I think. One so-called clue was a white scarf.
Does anybody know what movie this was?