Mike Carpenter, the bouncer at the Coachlight who'd seen Debbie in the parking lot with Glen Gore around 12:30 that morning, was one of the first to volunteer evidence.
-- Narration (chapter 1)

Importance: This line of narration reiterates the fact that Glen Gore is the most likely suspect in the case of Debbie Carter's murder. However, the police refuse to investigate Gore, and they instead investigate Ron Williamson and Dennis Fritz, despite the fact that there is no evidence linking either of those two men to the crime.

The murder rocked Ada.
-- Narration (chapter 1)

Importance: This line of narration emphasizes the sense of shock and fear that settled on the town of Ada following Debbie Carter's murder. The police were under immense pressure to solve the murder, and this pressure likely contributed to the unethical and illegal tactics they used to make it appear that they had solved the murder.

The police also interviewed a man named Dennis...
-- Narration (chapter 4)