Was watching on TCM tonight and wouldn’t you know, I missed the ending. Sandra Dee is being chased by Anthony Quinn, he breaks down the door, she is out the window standing on the roof…her boyfriend John Saxon is driving away and she calls to him…and then what?
AQ comes out follows SD begging her to come take his hand. Blake hears her, park jumps from car. SD goes from window to window trying to find one open so she can get back into the house. LT leans out the window SD and AQ left from imploring AQ to come back. SD opens a window to climb back in. AQ turns toward the window where LT is and . . . loses his balance and falls to his death. Blake runs over to his crumpled body then looks up to LT. The last scene is “A Portrait in Black” of a distraught LT at the window. The End
Sorry it took so long for the reply; but I enjoyed watching the movie. 
Oh, thank you! I wasn’t expecting any reply at all! … I enjoyed this movie, too, even if Anthony Quinn was horribly miscast, there was a lot more ‘action’ in it than I expected. “I can’t drive!” “This pedal makes the car go, this pedal makes the car stop, now follow me!”
I love old movies! This one makes me think how murder is the “Lays Potato Chips” of crime.
I still need to see the end of “This Could Be the Night”; but it has been so long since I saw it and missed the end that I need to watch it all over again.
Sure are a lot of people falling to their deaths in old movies.