What is the style of the movie?

Shadow of a Doubt is a classic Alfred Hitchcock film. He considered it to be the greatest of his films, and many viewers would agree. He uses many of his famous techniques, and although we suspect the truth about Uncle Charlie long before it's revealed, our suspense continues to grow.

The "MacGuffin" is a type of plot device used by Alfred Hitchcock in most of his films, including Shadow of a Doubt. A MacGuffin is an element in the plot that serves no other function than to motivate the characters and instigate the plot. It is not integral to the plot itself, but instead serves to push the action forward through affecting the characters. For instance, in the famous film Vertigo, the MacGuffin is a woman who died, and her death starts off a series of events. Although the instigating detail becomes less important than the events in the plot, the action is instigated and pushed by this MacGuffin.