Causes of Wrongful Convictions

A wrongful conviction not only devastates the innocent person and their loved ones; it diminishes the integrity of the justice system and harms the public good. Police are led away from the real perpetrator, public safety is put at risk, and justice is not achieved.


Eyewitness Misidentification
Eyewitness misidentification is the leading cause of wrongful convictions in the United States. Over 75 percent of DNA exoneration cases have involved convictions based on mistaken identification evidence. A variety of factors can affect the reliability of an identification, mainly the simple fallibility of human memory.


Unvalidated Forensic Science
Forensic science is a useful tool, but many forensic disciplines apply techniques and methods that have not been approved by the scientific community. Unvalidated forensic science, such as hair and fiber comparison and bite-mark analysis, have played a role in over 50 percent of convictions later overturned by the use of DNA evidence, proving that there has to be higher standards for forensic testimony at trial.


False Confessions
Innocent defendants have made incriminating statements, confessed, or plead guilty in approximately 25 percent of DNA exonerations in the United States. Multiple factors can contribute to false confessions, such as a defendant’s poor mental health and/or the use of coercive interrogation techniques. These factors result in an often threatened and confused defendant, who will confess to the crime in an attempt to relieve their current discomfort.


Snitch Testimony
In 15 percent of convictions later overturned using DNA evidence, the defendant was imprisoned because an informant or ‘snitch’ testified against them. Snitches often have incentives to lie on the stand in order to escape prosecution themselves or receive shorter sentences. Snitch testimony is especially dangerous when such incentives are not disclosed to the jury, so they do not understand it could be bias. It is important to regulate the use of incentivized informants, or snitches, as to reduce the possibility that these unreliable witnesses mislead judges and juries.

Read the Kaufman Commission Report on Proceedings involving Guy Paul Morin


Police and Prosecutorial Misconduct
While most prosecutors and law enforcement officials are honest and have the best intentions to protect society, the pressure to secure a conviction at times may lead police and prosecutors  to act in an inappropriate, unfair, or unlawful manner. This government misconduct can include withholding or fabricating evidence, coercive interrogations by investigators, or suggestive methods used by police to obtain an identification. While police and prosecutorial misconduct is more likely in high profile cases with a great amount of press coverage, because law enforcement feels pressure to obtain a suspect.
In the case of Kenneth Waters, for example, the Ayer police both fabricated and withheld critical evidence and threatened witnesses to implicate Kenny, leading to his wrongful conviction. DNA tests proved Kenny’s innocence, and he was exonerated in 2001 by his sister, Betty Anne Waters, with help from the Innocence Project.


Poor Defense Lawyering
Defendants are guaranteed a right to counsel but an ineffective defense attorney can lead to the wrongful conviction of a factually innocent person. Inadequate defense lawyering can include the overall failure to prepare for trial, to investigate the crime and the defendant’s alibi, and to challenge witnesses and experts.