Professor Lawrence Marshall discusses in a Chicago Tribune article about being wary of confessions that are forced by authorities:

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.

...

“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-founded Northwestern University’s Center on Wrongful Convictions.

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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.