Police Arrests in "North By Northwest"
I know that people often dismiss plot questions in Hitchcock films, saying that Hitchcock didn't care about the plot and neither should we. Still, when I see a celebrated film and don't understand the plot, I do always wonder whether I've simply missed the point.
The assassin kills the real United Nations diplomat with a knife, apparently to precipitate Rogers's arrest for murder. At the auction, Roger deliberately gets picked up by the police to thwart Vandamm, and then tells the police that he's the killer from the United Nations. Why do Leonard and Vandamm sometimes want Roger in police custody, and sometimes not want this?
Best Answer
At various points in the time-line they want Roger to take the fall for the killing, and then they want it to be easier for them to silence him permanently.
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Answer 2
The criminals never wanted Roger in police custody. Vandamm never loses confidence that Roger is actually a US agent named Kaplan, and believes that the police would only help him. Later in the movie, near Mount Rushmore, Vandamm says "Not at all. I knew the police would release you, Mr. Kaplan."
So what was the change that led the assassin to kill the real Townsend at the UN? Well, Roger has just informed him that there are criminals impersonating him and living in his home. From the assassin's perspective, their hideout in Townsend's home is now compromised and Townsend himself is a liability.
Your question does make me doubt a different scene however; when Roger returns to the Townsend manor and the fake Mrs. Townsend convinces the police that Roger is just a drunk. If Vandamm was certain that Roger was a government agent and had police support, why would he construct a ruse and attempt to fool the police?
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