The problem with false confessions, experts say, is that many people – even people within the criminal justice system – find it hard to comprehend that a person would actually admit to something that he didn't do. But it happens, and not rarely. According to the Innocence Project, 25% of wrongful convictions overturned by DNA evidence involve a false confession. And many of those confessions actually contain details that match the crime – details that were not in the public domain, says Saul Kassin, a social psychologist and expert in false confessions who is a professor at John Jay College of Criminal Justice in New York. The problem is that all of those details are already known to police, and through the process of interrogation those details can, and do, shape a person's confession, with police – purposely or inadvertently – divulging details of the crime.
Once a confession is made, it's incredibly powerful, say Kassin and others who study false confessions and the tactics that lead to them; jurors often consider a confession infallible evidence, he explains, even though research clearly demonstrates that is not always the case. Among the most vulnerable suspects are those actually innocent, Kassin points out – in many ways, innocence is their enemy. "When I ask innocent people, 'First of all, why didn't you lawyer up?' they tilt their head and look at me like I'm crazy ... and say, 'Well, I didn't need a lawyer, I didn't do anything wrong,'" he says. "They volunteer to take lie detector tests, they volunteer their keys, their shoes, their cars, and they just don't apprehend that there is any risk. And their explanation is as simple as, 'I didn't do anything wrong, I have nothing to do with it, I have nothing to fear, I have nothing to hide – in fact, the more they get to know me, the more they'll see that I didn't do it,'" he continues. "People believe in the transparency of their innocence."
The problem can be compounded by the fact that police generally believe they have a good sense for determining which of the people they encounter during an investigation should be elevated to suspect status. In fact, according to research done by both Kassin and by Iowa State University psychology professor Christian Meissner and others, police are actually no better at determining who is lying to them than are untrained laypeople. Indeed, some of the signs police are trained to believe indicate deception, and techniques they're taught to use in interrogations, may negatively impact their ability to determine lies from truth.
The dominant method of interrogation used in the U.S. is known as the Reid Technique, named after its originator, former Chicago cop John Reid. It's an adversarial and persuasive technique designed to yield compliance from suspects – police are taught to assess in a first interview whether a person should be considered a suspect and then, once that determination is made, to not allow the suspect any ability to deny their involvement in the crime. "It is an excellent ... psychological approach to getting confessions from criminals," Kassin says. "I think the problem begins with this. I always say this: If every person interrogated was the criminal, the Reid Technique would be perfect. The problem is [police] often bring innocent people into the interrogation room." (In fact, during one early use of the technique by Reid himself, a false confession was extracted from a man whose wife had been murdered; it took more than five decades for the man to be exonerated.)
Police have long been taught, for example, that nonverbal cues, like hair touching, leg bouncing, and shifting eye movements, indicate deception. The research says otherwise. "These things ... are in the folklore of police training," says Meissner, but "there is plenty of research to show that they're not reliable." Also problematic are techniques police are allowed to use inside the interrogation room – including techniques that "manipulate the perception of consequences," says Melissa Russano, a professor of criminal justice at Roger Williams University. Specifically including lying to a person about evidence – saying that a fingerprint or DNA ties a person to a crime, when in fact no such evidence exists – or implying leniency, "stressing the importance of cooperation [with police] ... [suggesting] if you cooperate, things will be better for you and if you don't, things are going to get worse," Russano details.
Taken together, investigation detail leakage, faulty assumptions about who is lying, and heavy-handed, perception-altering interrogation tactics increase the likelihood of a false confession.
According to Russano, current research reflects that the heavy-handed tactics traditionally taught to police investigators are less effective and riskier than more information-based approaches, in which detectives use investigative interviewing and rapport-building techniques – open-ended questioning, timeline-building, and fact-checking. "Really, the science is showing that it's about how people tell their stories and how they remember events" that can reveal whether a person is lying, says Meisser. "It's about the cognitive properties of how they tell their stories that tend to be very important." This less adversarial approach is widely used elsewhere in the world, but U.S. police retain their decades-old reliance on the abrasive, unscientific, old-school approach.Of a half-dozen recommendations by the Timothy Cole Advisory Panel on Wrongful Convictions, the last one the Texas Legislature has not yet acted on is a requirement to record custodial police interrogations in serious cases. One hopes that this case and other examples of coercive interrogation techniques will spur the Legislature to rectify that oversight when the 84th session convenes in 2015.
Regardless of the technique, however, each confession should be tested for reliability by seeking corroborating evidence. And the very best form of corroboration, says Kassin, is when a suspect provides a detail or fact that police did not already know. "So, if he leads the police to the body, or to the murder weapon, or to whatever was stolen, that is gold-standard, corroborated evidence."