Police use of bright lights, rubber hoses and other physical methods to extract confessions was once common in North America. Court decisions since that time have rendered such confessions inadmissible, leading to the abandonment of such techniques. Trial judges have even rejected confessions obtained though threats of long sentences or promises of short sentences. Police now generally use psychological pressures, which may well be more effective.

In a disturbing number of DNA exoneration cases, defendants have made incriminating statements or delivered outright confessions. Many factors arise from interrogation that may lead to a false confession, including: duress, coercion, intoxication, diminished capacity, ignorance of the law, and mental impairment. Fear of violence (threatened or performed) and threats of extreme sentences have also led innocent people to confess to crimes they did not perpetrate.

Confessions can generalized in three categories:

• Voluntary: involving no external pressure
• Coerced-compliant: suspect confesses, believing that confession will lead to a better outcome than not confessing.
• Coerced-internalized: suspect is induced to believe he or she is guilty.

Police and courts often deny that the second two categories actually exist.

Tactics such as feigned sympathy and friendship towards victims, appeals to religious beliefs, blaming the victim or an accomplice, intimidation, overstating or understating the seriousness of the offense and the magnitude of the charges, presenting exaggerated claims about the evidence, falsely claiming that another person has already confessed and implicated the suspect and wearing a person down by a very long interview session have been used by officers trying to elicit a confession. The result is that some individuals confess to crimes they did not do. Sometimes they even grow to believe that they are guilty.

Some police departments use a 1985 book, "Criminal Interrogation and Confessions," as a reference. It recommends isolating the suspect, and involving the suspect in possible crime scenarios because "an innocent person will remain steadfast in denying guilt." An innocent man will not confess to crimes in these scenarios because of guilt, but because of misinformation and intimidation.

The systemic problems that contribute to convictions of the innocent become visible only after innocence has been established. Whatever problems there may have been in a case cannot be analyzed for the simple reason that the cases themselves are have not been brought to the attention of the proper authorities. Another issue is that every problem that may be contributing to the wrongful convictions is unknown. For instance, when a witness commits perjury he or she might do so because of police or prosecutorial misconduct. While the perjury may be plain, however, precisely why it occurred may not.

The Supreme Court decision in Miranda vs. Arizona (link) produced what is now known as the Miranda warning (link), which is intended to prevent interrogation techniques that tend to produce false confessions. And indeed, 36 years ago, when the decision was handed down, those on the front lines of law enforcement had vigorously argued that the ruling would handcuff them and result in far fewer confessions and thus convictions. Today, those who once complained have come to embrace Miranda. Why the change of heart?

The answer lies behind the long-locked doors of the interrogation room. What the Court did not foresee was how its decision would lead to new, questionable interrogation methods. Most people know the "good cop-bad cop" routine popular with police drama writers (and less so with police themselves).

DNA testing, which can identify a person indisputably (or indisputably rule that person out) based on a single strand of hair or tiny scrap of skin, has taught us that there are people in prison, including some on death row, who are not just undeserving of their punishment for some legal, political, or psychological reason, but plain-and-simple, not guilty. The Innocence Project at Cardozo Law School, led by Barry Scheck and Peter Neufeld, has achieved a steady stream of murder-conviction reversals. As intended, this has given many people pause about an irreversible sanction like the death penalty.

Useful Links:
   -Former Death Row Inmate Sues; Suit Claims Civil Rights Violations
   - Innocence Project: False Confessions
   - CBC News: Inside the Interrogation Room