Principle of avoiding premature identification of suspects in investigation

The principle against premature suspect fixation holds that investigators must form theories without allowing an early guess to dictate what they can see. In the account Andrew Barber gives at trial, incomplete evidence makes some hypothesis unavoidable; the danger begins when the chosen suspect becomes the frame through which all subsequent information is read. The principle is therefore not a ban on focusing an investigation, but a warning that focus can harden into confirmation bias and conceal the possibility that the first answer was wrong.

The Problem of Incomplete Evidence

Andrew describes the process as a response to uncertainty. In a difficult case, investigators do not possess all the evidence, the data remains incomplete, and no clear pattern may point to an obvious answer. Detectives, like other people, form a narrative or theory and then look through the available information for support. Once they choose a suspect, they may stop noticing evidence that points toward someone else.

That account makes the danger more subtle than simple carelessness. A theory is needed to direct attention and organize inquiry, yet the same theory can narrow attention until contradictory possibilities disappear from view. The investigative narrative is provisional in principle; in practice, it can begin to feel like a conclusion before the evidence has earned one.

A Rule, Not a Ban on Theories

Under questioning by Neal Logiudice, Andrew acknowledges that detectives have to form theories and focus on suspects, often before they have clear evidence against them. He does not offer an alternative method that would eliminate guessing. Instead, he names the dilemma: an investigation starts with a guess, and sometimes the guess is wrong. The practical rule is to be wary of locking onto one suspect too soon, because a mistaken choice can cause investigators to miss even obvious evidence pointing toward the right answer.

When Logiudice asks whether anyone made the wrong guess in this case, Andrew cannot settle the issue. His answer is that they did not know. That uncertainty matters: the principle does not itself identify the killer or prove that one particular investigative decision was mistaken. It marks the limits of what the available inquiry can establish and insists that unresolved alternatives remain visible rather than being treated as disproved.

The Students’ Interviews and the Limits of Reading Behavior

The rule also bears on the interviews conducted after Ben Rifkin’s murder. At two o’clock, Andrew and Paul Duffy took over the principal’s office to interview high-priority witnesses: Ben’s close friends, students known to walk to school through Cold Spring Park, and children who had asked to speak with investigators. Two dozen interviews were scheduled for them, while other CPAC detectives interviewed students at the same time. The initial expectation was modest: most conversations would be brief and yield little.

After only three or four interviews, Andrew and Duffy suspected that the students were withholding information. At first they read the familiar shrugs, wandering eyes, and evasions as ordinary adolescent behavior. The more consequential signal was that some children denied not only knowing anything about the murder but knowing Ben at all, despite investigators’ knowledge that he had friends. Andrew understood those denials as lies and felt that Ben’s friends were disowning him. Yet the scene also exposes a difficulty built into the principle: interview behavior is not self-interpreting. Some students appeared direct and confident when lying; others seemed more self-conscious. Manner could raise suspicion, but it could not by itself determine what had happened or which suspect was responsible.

Patz as an Alternative—and as a New Fixation

Leonard Patz becomes a concrete test of Andrew’s warning about a suspect being overlooked. Andrew says that he increasingly believed Patz had killed Ben, and he could not understand why Logiudice preferred Jacob Barber as the defendant. In August, Andrew followed Patz for weeks, before and after his workday, hoping to find harder evidence than Matt Magrath’s information, which Andrew considered compelling but unusable in court. He wanted something that could independently support the suspicion rather than depending on Magrath’s word.

The surveillance produced no distinctly suspicious act. Patz went to work at Staples, spent time in shops or his apartment near Cold Spring Park, ate at a McDonald’s on Soldiers Field Road, and once went to a movie alone. Andrew acknowledges that none of this was significant, but the absence of incriminating behavior did not weaken his certainty. He became increasingly absorbed in the possibility that Jacob would be sacrificed to protect Patz, interpreting Patz’s otherwise uneventful routine as a reason to suspect that he was lying low. The episode gives the principle an uncomfortable double edge: resisting fixation on Jacob could open attention to an alternative suspect, but Andrew’s own conviction about Patz could also become resistant to disconfirmation.

The Principle’s Unresolved Stakes

The book does not present the rule as a guarantee that investigators will discover the truth. It offers a discipline of attention: test the story formed from incomplete information, remain alert to evidence pointing elsewhere, and recognize that a confident interpretation may still be wrong. The testimony’s final uncertainty—whether anyone guessed wrong in this case—keeps the principle from turning into a verdict about the investigation. Its force lies instead in the gap between having to choose where to look and knowing, only after the fact or perhaps never, whether that choice blinded the investigators to what mattered.