You intended to fish until the morning of the seventeenth, at which time, if you’d decided to come forward, at least sixteen hours would have passed since you’d heard of the death of Carl Heine. So let me put this another way, a bit more consistent with reality -- did you, Mr. Miayamoto, intend to come forward? (Guterson. ch. 28).
What is the primary purpose of the author's use of italics in the above quotes?