Final answer:
Dupin's decision to not reveal his suspicions at this point in the story may serve to build suspense and maintain the mystery. He may be waiting for the right moment to reveal the truth and catch the murderer.
Step-by-step explanation:
Dupin's decision to not reveal his suspicions about the murderer at this point in the story may serve multiple purposes. One reason could be to build suspense and maintain the mystery surrounding the crime. By keeping the reader and the narrator in the dark about his thoughts, Dupin adds to the intrigue and excitement of the narrative. Additionally, Dupin may not want to disclose his suspicions until he has gathered enough evidence to support his claims. He may be waiting for the right moment to reveal the truth and catch the murderer.