Carlos DeLuna and Cameron Todd Willingham probably did not commit the crimes for which they were put to death by the state of Texas. In-depth inquiries into their convictions revealed bungled investigations, poor recordkeeping, mistaken eyewitness testimony, spurious forensic testimony and misconduct by law enforcement personnel, among other problems.
Sadly, the DeLuna and Willingham convictions are hardly isolated incidents. The National Registry of Exonerations, which launched this month, lists 890 men and women who were wrongfully convicted for serious crimes and spent, on average, more than 11 years in prison before being found factually innocent. That's not the complete story. The registry does not include an additional 1,170 people who were exonerated following large-scale police scandals. The actual number of false convictions is probably far greater.
At bottom, the primary cause for false convictions is the questionable quality of the evidence habitually used in criminal prosecutions. Poor evidence can be produced even when all actors follow procedures diligently and conscientiously. The problems lie with the investigative procedures themselves. Lineups, witness interviews, and suspect interrogations rely on crude and archaic investigative methods that are both insensitive to the prospect of human error and prone to exacerbate mistakes. As a result, the evidence elicited contains an unknown mix of accurate and inaccurate evidence.
Mystifyingly, criminal investigators are not required to make a reliable record of the evidence they collect. Verdicts are thus often based on faded memories, paraphrased statements, incomplete narratives and swearing contests about what transpired in the interrogation room. Hints of error are obscured from police supervisors and prosecutors, and they are concealed from lawyers, judges and juries. The lack of a reliable record opens the door to testimony creep -- as the trial date approaches, gaps in testimony get filled, narratives congeal, and reluctant witnesses become more confident.
Fortunately, these problems can be easily fixed. First, investigations should be conducted in adherence with best-practice procedures, which are rooted in psychological experimentation. For example, lineups should be conducted only by officers who are blind to the identity of the suspect; interviewers should never suggest to a witness the desired response to their questions; and when trying to determine that a suspect is lying, interrogators should stop relying on folksy intuitions such as gaze aversion and nervousness.
Second, all encounters with potential witnesses throughout the investigative process should be electronically recorded, and the recordings should be screened in advance by police supervisors and prosecutors, and be shared with all involved parties.
Infusing the criminal justice process with more accurate and transparent evidence promises to reduce the incidence of both faulty prosecutions and frivolous defense claims, and thus also decrease the number of appeals, habeas corpus proceedings, civil suits and payouts for damages. Court systems would no longer have to spend precious resources on conjecturing what transpired in the interrogation room or in the back seat of a patrol car. Simply clicking the "record" button of a video camera would solve those quandaries.
The U.S. Supreme Court is the only body that could bring about the reforms needed to ensure the accuracy of criminal convictions nationwide. But in its view, the Constitution only offers criminal defendants a potpourri of procedural rights, not a rigorous commitment to determine their factual guilt. Indeed, the court has indicated that it would be reluctant to intervene in favor of a death-row inmate who provides a truly persuasive demonstration of innocence as long as he was offered the requisite procedural rights at trial.
Fortunately, an ever-increasing number of entrepreneurial states such as Illinois, North Carolina and New Jersey have moved to enhance the accuracy of their criminal justice systems, and similar reforms are being implemented by various local jurisdictions. Dallas County, Texas, is a shining example. The sitting district attorney and police chief have adopted protocols for harmonizing investigative procedures with scientifically proved methods, recording the bulk of their investigations and sharing the findings with the defense on an "open-file" basis. Once a hotbed of false convictions, Dallas County offers a criminal-justice process that is probably more fair and accurate than anywhere else in the country.
Absent an unlikely change of course by the Supreme Court, the rest of the nation would do well by following Dallas' lead to bring the U.S. criminal justice system into the 21st century.
Dan Simon, a professor of law & psychology at the Gould School of Law at the University of Southern California, is the author of "In Doubt: The Psychology of the Criminal Justice Process," to be published by Harvard University Press.