Here’s the write-up, from New Scientist:

“To the average person it’s inconceivable how a false confession can happen,” says Saul Kassin of the John Jay College of Criminal Justice in New York, who has been an expert witness in dozens of wrongful conviction cases. He says the suspect usually sees it as a short-term measure, thinking that when all the evidence is in, their innocence will become obvious. “They believe that in the end they won’t have to pay for the confession.”

Such a gamble is hard for juries to understand, he says, but the latest study might help. In this, 88 people did various computer tasks as part of a fake experiment, then either slept for 8 hours or had to stay awake all night. The next morning they were accused of losing all the study data by pressing the “Escape” key, something they had been repeatedly warned against.

“It’s not as awful as confessing to murder but some of these people feel really bad – they think the experiment is ruined,” says Elizabeth Loftus of the University of California, Irvine, who took part in the work.

When asked to sign a statement admitting their guilt, half of those who were sleep deprived complied, compared with only 18 per cent of those who got a night’s rest.

There are some clear limitations to any study of false confessions — there’s just no way to really replicate the conditions under which they’re typically given. But given those limitations, this study is pretty compelling. It’s also intuitive. Sleep deprivation is a common method of torture. And as with other methods of torture, people will say what they think they need to say to get relief. It’s not hard to see why innocent people might be more likely to confess when sleep-deprived, especially if they believe there’s other evidence out there that will later clear them. A guilty person has more incentive to endure the discomfort.

We should also be suspicious of information obtained through sleep deprivation because of what it does to the body. From Psychology Today:

One of the first symptoms of sleep deprivation in humans is a disordering of thought and bursts of irrationality.  Beyond 24 hours of deprivation people suffer huge drops in cognitive functions like accurate memory, coherent speech, and social competence. Eventually the victims suffer hallucinations and a total break with reality.

Whatever sounds come out of people’s mouths at that point, whatever words they may seem to be saying, have to count as the least reliable kind of information one could possibly conceive.  A mind tortured to that extremity will not provide anything that can be trusted as relevant to the real world.  Even if the person really knew some vital bit of information (e.g., the location of a ticking time bomb), prolonged sleep deprivation will make it less likely the person could accurately and meaningfully communicate that information.  Beyond a certain point the sleep deprived individual can no longer maintain enough cognitive coherence to say anything useful to anyone.

A recent study from the University of California-Irvine found that sleep deprivation can also make people susceptible to false memories, meaning that if coupled with suggestion, it not only can lead to a false confession, but also could make for a pretty convincing one.

The New Scientist article notes several cases in which a sleep-deprived suspect was later exonerated, including Damon Thibodeaux, who was wrongly imprisoned in Louisiana for 15 years. There’s also Daniel Anderson of Chicago, who spent 25 years in prison for a sleep-deprived confession. Frank Sterling served more than 18 years in a New York prison after falsely confessing to raping and killing a 74-year-old woman in 1988. His confession came after 12 straight hours of interrogation. He tried to explain what he was going through to New York magazine in 2010: “They just wore me down . . . I was just so tired. Remember, I hadn’t had any sleep since about 2:30 Tuesday night . . .“It’s like, ‘Come on, guys, I’m tired—what do you want me to do, just confess to it?’ It’s like, yeah—I wanted to get it over with, get home, and get some sleep . . . Eighteen years and nine months later, I finally get to go home.”

Sleep deprivation can even cause people to falsely admit to raping and killing their own children. Jerry Hobbs, an Illinois man who confessed to raping and murdering his daughter and her friend, spent five years in jail before he was cleared for the crimes. DNA had exonerated him after just two years, but citing his confession, prosecutors came up with bizarre alternate narratives to explain why the DNA found in the victims didn’t come from Hobbs. Because he was out looking for his daughter the night before his arrest, Hobbs hadn’t slept in 24 hours. After his arrest, he was interrogated for 20 hours straight, which means he’d gone nearly two full days with no sleep before confessing. Kevin Fox, another Illinois man, falsely confessed to raping and killing his daughter after 14 straight hours of interrogation. He remained in jail for eight months until DNA testing exonerated him and implicated another man for the crime.

The effects of sleep deprivation can also be intensified by withholding food, or if the suspect is a juvenile, has a low IQ or suffers from mental illness. All of which makes for a pretty convincing argument for recording police interrogations from start to finish — we need assurance that confessions are voluntary and reliable and that those damning details about the crime known only to the police and the perpetrator weren’t introduced (unintentionally or otherwise) by law enforcement officers.