What are the themes in chapter 6 of Frankenstein

Explanation:

Frankenstein finds a letter from his father informing him that his youngest brother William has been found strangled.  They thought the motive for the murder was the theft of a miniature portrait of their mother that William was wearing round his neck. Elizabeth blamed herself for allowing William to wear the miniature and leaving him alone in the country. Frankenstein immediately left for Geneva, stopping by on the way to visit the site of his brother's death. He found the creature there and realized that he was William's murderer. He hesitated to raise the alarm because he felt that no one would believe him. When he reached home, he felt bad for Justine, who was arrested and suspected of the murder. Justine was awaiting her death and Frankenstein felt guilty.