Murder can be made to look like suicide, and suicide can be made to look like murder.
-- Benjamin (Chapter 1 paragraph 20)

Importance: This statement is repeated frequently throughout the novel and seems to be one of the themes of the book as several people die of murder, but their deaths are set up as a suicide.

You’re not like everyone else, Benjamin. You never were. Even before — well, even before everything happened with your mother.
-- Marty Casper (Chapter 4 paragraph 12)

Importance: Even though his father told him that he was different from other people, Ben didn’t really know what his father meant at this point in the novel.

I came away with three things I didn’t previously know. First, the Metropolitan Police Department is treating Diana’s death as a homicide investigation. Second, they’re acting like they’re not, for some reason.
-- Benjamin (Chapter 8 paragraph 22)

Importance: Benjamin visits Diana’s home with the intention of taking the surveillance equipment he had...