Opinion: Criminal probes must seek truth

Every law enforcement agency owes a duty to review, investigate, and assess post-conviction exculpatory facts that may have led to a wrongful conviction.

College courses in criminal justice teach it, police policies proclaim it, detectives and investigators are instructed in it: “The fundamental purpose of a criminal investigation is to find the truth.” This cornerstone of all law enforcement investigations reflects a principle ensuring investigators remain faithful to their oath of office and its accompanying ethical standards by only arresting and pursuing prosecution of the guilty. However, in post-conviction investigations, law enforcement’s “truth-seeking” role is, at best, confused; at worse, it undermines the truth-seeking obligation.

As forensic science evolves, and in the case where subsequent findings are exculpatory, vindicating someone convicted of a crime as innocent imposes on the police an obligation to act. Every law enforcement agency owes a duty to review, investigate, and assess post-conviction exculpatory facts that may have led to a wrongful conviction. Sadly, the wrongfully convicted serve an average of 14 years in prison before exoneration and release.

In “Forensics Under Fire”, Jim Fisher notes that we have known advances in DNA have uncovered other forensic disciplines’ problems for a significant period. For years, experts overreached regarding the evidentiary value of hair and bite-mark evidence. Hundreds, if not thousands, of criminal defendants have been imprisoned on what many experts now consider unreliable forensic science. Using latent prints, believed the gold standard of forensic science, has come under attack because of a handful of misidentifications.

The citizens we serve rightfully expect that police will review and investigate post-conviction cases where they learn of facts indicating previous evidence examination processes were unreliable or where they discover other exculpatory information warranting further inquiry.

And to that point, all law enforcement agencies should have a policy defining and establishing criteria and guidelines for conducting post-conviction investigations to ensure they serve the ends of justice. Such policies should include an internal protocol for identifying flaws in the initial investigation or to determine that scientific evidence has yielded undependable results.

A post-conviction investigation’s objectives are two-fold: First, to review and investigate all currently available evidence and report such evidence that supports the innocence of the individual initially charged and convicted of the crime; second, to diligently work to identify the person responsible for the crime and, if they develop probable cause for such an arrest, to accomplish the arrest.

Finally, police leaders must have the personal courage and professional independence to challenge anyone who might seek to compromise those standards. The police should lead the charge in freeing anyone convicted wrongfully. We always must be on the side that seeks the truth.

Louis M. Dekmar is police chief of LaGrange, Ga.