Consider this scenario: "A man with a low IQ confesses to a gruesome crime. Confession in hand, the police send his blood to a lab to confirm that his blood type matches the semen found at the scene. It does not. The forensic examiner testifies later that one blood type can change to another with disintegration. This is untrue. The newspaper reports the story, including the time the man says the murder took place. Two witnesses tell the police they saw the woman alive after that. The police send them home, saying they “must have seen a ghost.” After 16 years in prison, the falsely convicted man is exonerated by DNA evidence."
This situation is what John Jay College of Criminal Justice psychologist Saul Kassin is afraid could be happening in some cases, according to a study he published in the journal Psychological Science. Investigating the potential for this occurrence in past court cases Kassin along with with Daniel Bogart of the University of California Irvine and Nova Southeastern University’s Jacqueline Kerner reviewed the trial records of 241 people exonerated by the Innocence Project since 1992, which was instituted to help exonerate wrongly convicted people through DNA evidence.
Of the those exonerated in the researcher's review, 59 (25 percent) provided false confessions and 75 percent involved eye witness mistakes:
The analysis revealed that multiple errors turned up far more often in false confession cases than in eyewitness cases: 69 percent versus fewer than half. And two thirds of the time, the confession came first, followed by other errors, namely invalid forensic science and government informants.
Kassin believes the findings “greatly underestimate the problem” because of what never shows up in court: evidence of innocence. Told the suspect confessed, “alibi witnesses back out, thinking they’re mistaken,” police stop searching for the real culprit. “We show that confessions bring in other incriminating evidence that is false. What we don’t see is a tendency to suppress exculpatory evidence.”
According to Psychological Science, many states do require confessions to be taped to ensure coercion isn't a factor. Kassin thinks that with the evidence this study provides, judges and juries should be encouraged to think about the "conditions" under which the alleged suspect confessed in order to maintain objectivity with the other evidence provided to them.
[H/T Science Daily]