A group of Herb Clutter’s hunting companions arrive at the Clutter home with a grim mission: to clean up the traces of the grisly murder. Alfred Stoecklein, who worked for the Clutters and lived not a hundred yards from the main house, lets them in. He has to keep explaining that he could not have heard the gunshots because of the wind and also because of the barn situated between his house and the Clutters’. The men burn the couch, mattresses, pillows, and other items that have been soaked in blood. They feel shock that a man they knew well has been the victim of such a ghastly crime.

Alvin Dewey is put in charge of the investigation. Having served in the Kansas Bureau of Investigation for several years, Dewey knew Herb Clutter personally. From the autopsy reports, it is determined that the victims were killed between 11:00 p.m. Saturday and 2:00 a.m. Sunday morning. Neither Mrs. Clutter nor Nancy were sexually molested. It is impossible to determine the order of the killings. Dewey devises separate theories as to the number of murderers. If there was a single killer, Mr. Clutter was most likely drafted into tying up his family. More likely, according to Dewey, two murderers joined in the killing. There are very few clues beyond the footprints of blood and dust on the cardboard on which Mr. Clutter was found. Dewey pours over the crime scene photographs, hoping that some clue will pop out to give him some direction. He calls his wife, who used to work for the FBI and is used to her husband’s odd hours. She tells him she has had the locks on their house doors changed.

Residents of the town of Holcomb give way to fear. They begin to lock their doors, which they never felt they had to do. They look at each other with suspicion. As people move past the Clutters’ reputation as a popular, highly respected family, they begin to remember incidents in which Herb Clutter made some enemies. Arthur Clutter, Herb’s brother, is sure the killer is within a ten-mile radius. However, four hundred miles to the east, Perry and Dick dine together at a restaurant in Kansas City. Perry is fascinated by the newspaper report of their crime. He has difficulty believing that the police have found no clues, though Dick tells him to relax: they have committed the perfect crime.