Studies and surveys have found that both minors and the mentally impaired are more likely to make false confessions, in part because they are more vulnerable to suggestion. A recent study conducted by Northwestern University law professor Steve Drizin and UC Irvine criminologist Richard Leo examined 125 cases in which individuals were exonerated after giving false confessions. The researchers found that 32% of the cases involved minors and 22% of the cases involved individuals with mental retardation. "They are more likely to go along, agree and comply with authority figures - to say what the police want them to say - than the general population," notes Emory University professor Morgan Cloud, who co-wrote another study that found that the mentally impaired - even those who with mild forms of mental retardation - are largely incapable of understanding police admonitions of their right to remain silent and to have an attorney.

A study published in the University of Chicago Law Review examining comprehension of Miranda rights found that only 27% of disabled persons understood that confessions can be used against a suspect, while 91% of nondisabled persons understood this concept. Disabled subjects were also found to be far less likely to understand that police cannot threaten suspects, that police and judges cannot force suspects to talk, and that there is no penalty for remaining silent. While juveniles and those with mental impairments are most likely to succumb to psychological pressure and make erroneous admissions during intense police interrogations, experts note that even the able-minded are at risk. Social scientists and legal experts say the best way to ensure that confessions or admissions are truthful is to require detectives to tape them from the Miranda warning in the first interview until the end of all subsequent interviews. Some states, including Alaska and Minnesota, already require this type of videotaping. UC Berkeley sociologist Richard Ofshe notes that video or voice recordings of confessions would reduce false confessions by as much as 90% because it would stop coercive tactics that are sometimes used by police.