What causes people to give false confessions?

After 14 hours of interrogation in a small, windowless room, Kevin Fox simply gave up. He knew he hadn't sexually assaulted or murdered his 3-year-old daughter, but police had rejected his requests for a lawyer and told him they would arrange for inmates to rape him in jail, according to court records.

The distraught father later testified that detectives also screamed at him, showed him a picture of his daughter, bound and gagged with duct tape, and told him that his wife was planning to divorce him, the records show.

Fox finally agreed to a detective's hypothetical account of how his daughter, Riley, died in an accident, thinking investigators would realize that the phony details didn't match up with the evidence, his lawyer said. Instead, he remained in Will County jail for 8 months, released only after DNA evidence excluded him as a suspect. In May, another man was charged with the crime.

What could be a similar story is now unfolding in Lake County, where Jerry Hobbs III, 39, is accused of murdering his 8-year-old daughter and her 9-year-old friend. Hobbs, who had a criminal record, has been in jail five years, in large part because of a confession that emerged after hours of high-pressure interrogation. Prosecutors planned to seek the death penalty in his October trial, even though his DNA did not match semen found on his daughter's body.

Authorities recently matched the DNA with another man accused of rape and robbery in Arlington, Va., offering Hobbs a chance at exoneration and once again raising the possibility that police coerced a suspect to falsely confess.

Both cases raise a question: Why would anyone confess to such horrific crimes — especially involving their own child or loved one — if they didn't commit them? Seemingly unfathomable, it happens far more often than most people believe, experts say.

"The interrogation itself is stressful enough to get innocent people to confess," said Saul Kassin, a psychology professor at John Jay College of Criminal Justice in New York. "But add to that a layer of grief and shock and perhaps even some guilt — 'I should have been there' — and then that the parent is trying like hell to be cooperative because they want the murder of their child solved."

Trauma, lack of sleep and highly manipulative interrogation techniques are a few factors that can cause the most level-headed people to falsely confess to a crime — even one as heinous as a child's murder, according to experts. Researchers believe that false confessions lead to about 25 percent of wrongful convictions, a statistic underscored by the increasingly sophisticated use of DNA evidence.

Over the past two decades, 254 people have been exonerated by DNA evidence, including 17 who were on death row, according to the Innocence Project, a nonprofit legal clinic based at Yeshiva University in New York.

"We know that for certain kinds of people, particularly those with mental illness and mental deficiencies, but other people as well, the psychological intensity of an interrogation can prove absolutely as torturous as physical pain," said Lawrence Marshall, a Stanford University law professor who co-foundedNorthwestern University's Center on Wrongful Convictions.

Confessions carry powerful weight with juries, and, as shown in the Hobbs case, they also strongly influence authorities. In 2008, Lake County Judge Fred Foreman agreed with prosecutors that Hobbs should remain imprisoned without bail, despite the revelation that his DNA did not match the semen found on his daughter's body.

Prosecutors suggested that Hobbs' daughter Laura had gotten the DNA in her body because she was found in a wooded area where people apparently go to have sex — in spite of the fact she was fully clothed.

Lake County prosecutors have not said if they have ruled out Hobbs as a participant in the crime, but they announced they're renewing their investigation in light of the DNA evidence.

In the Fox case, the Will County Sheriff's Department plans to hire an outside firm to evaluate its procedures and determine if they need to be changed.

"Obviously, there were some things that went wrong in this investigation," the sheriff's spokesman, Pat Barry, said. "We are in the process now of vetting a couple of firms … that will come in and review the Fox case for us."

Confessions that are not backed up with corroborating evidence should be viewed as suspect, Marshall said.

"I think what we are seeing right now is there has become an overdependence on confessions," said Marshall, who is appealing the case of Juan Rivera of Waukegan, who in May 2009 was convicted for the third time of the rape and murder of an 11-year-old girl despite DNA evidence that excluded him. Lake County prosecutors suggested the girl was sexually active to undercut the DNA.

While law enforcement agencies have long relied on the "Reid Technique" method of interrogation to elicit confessions, some critics argue it's based on faulty assumptions of deceptive behavior. Investigators are taught how to base their questions and method of interrogation on a suspect's verbal and non-verbal cues and mood, sometimes using a "baiting" approach to elicit confessions.

Even those who believe such techniques are effective in obtaining true confessions say they can be misused by authorities.

"There is a lot of coercion that can happen, short of the (former Chicago police Cmdr. Jon) Burge case where they are torturing someone to get confessions," said Fred Hunter of Hinsdale, a licensed polygraph administrator. Burge, 62, was convicted last month of obstruction of justice and perjury for lying about torturing suspects in a civil case.

Those most vulnerable to overzealous police work often are "throwaway people," said Hunter, referring to suspects who lack education, advocates or resources to represent themselves.

Dr. Robert Galatzer-Levy, a psychiatrist on the faculty of the University of Chicago and the Chicago Institute for Psychoanalysis, said interrogations are designed "not simply to get information," as the police often portray them. Instead, he said, interrogations are "well-thought-through psychological manipulations to get a confession."

Police do that by first developing a rapport with suspects. They then give them their Miranda rights, though in such a way that suspects feel they are being uncooperative if they invoke them. Finally, he said, police confront a suspect, saying they know he committed the crime but offering a way out that acknowledges guilt but to something less heinous.

The stress that comes with the death of a child, as in the cases of Hobbs and Fox, makes it all the worse. In such cases, experts say, it is natural for the police to focus their attention first on the child's parents or siblings. Many murders of children, it turns out, are committed by family members.

"People all say, 'I'd never confess. Not in a million years,'" said Galatzer-Levy. "But it turns out that people who are vigorously interrogated will confess — even if they're innocent. The terrified but rational person might give police a story just to end the interrogation, or because they think it might improve their situation."

Richard Leo of the University of San Francisco law school said no research has been done on whether the death of a family member makes a suspect more susceptible to interrogation. But, he said, "it kind of stands to reason. They're grief-stricken. They're distressed. They've often not gotten a lot of sleep. Those are all conditions that contribute to false confessions."

In the book "True Stories of False Confessions," Rob Warden and Steven A. Drizin of the Center on Wrongful Convictions write that reasons for false confessions range from desperation suspects feel as they endure lengthy interrogations to police exploiting suspects' mental handicaps.

Warden draws parallels between the case of Fox and Hobbs. In May, officials announced DNA matched a sex offender, Scott Eby, who has been charged in Riley Fox's murder.

Fox and Hobbs were accused of killing their children, leaving the two fathers especially distraught and more vulnerable to what Warden called "the emotional and intellectual manipulation that interrogators are taught to use."

Hobbs' interrogation ran for close to 20 hours. Although both confessions were videotaped, the interrogations were not — even though a new law had been signed that required the videotaping of interrogations in murder cases. The law at that point had not gone into effect.

"You can't imagine you'd ever confess to something you didn't do," said Warden. "But at some point people simply lose their will to resist. That's the danger of prolonged interrogation."

What's more, police often have preconceived notions of how a father, say, should react to the death of a child. When a suspect's behavior strays from those notions, police may ratchet up pressure.

"Either you're crying too much or you're not crying enough," said Warden. "Both touch off suspicion. You can't win either way."