How does Shelley build suspense in Chapters 21-22

I think the suspense begins to build at the end of chapter 20. Victor arrives on a small skiff. A crowd of people observes his approach with suspicion; they rain verbal abuse upon him and cry that he is a villain. A bewildered Frankenstein is told that he must go see the magistrate, as he is suspected of being responsible for the death of a man who was found murdered the previous night.