Credit: Baltimore Police DepartmentCredit: Baltimore Police DepartmentThree cheers for the Baltimore Police Department, which announced that it will henceforth present sequential double-blind photo lineups to witnesses during investigations. The practice guards against false identification.

According to the Innocence Project, “witness misidentification is the single greatest cause of wrongful conviction nationwide.” False identification played a role in 73 percent of the 311 cases where DNA evidence ultimately led to an exoneration.

Criminologists and psychologists have long advocated sequential double-blind lineups—where neither the witnesses nor the investigators showing them the photos know if a suspect is included—because police can unintentionally influence witnesses. “Detectives are emotionally involved in the case as well as the victims,” Baltimore Deputy Commissioner John Skinner tells CBS Baltimore.

Moreover, instead of presenting multiple photos at once, police will present mug shots sequentially. Presenting images simultaneously can also lead to misidentification.

In addition to devastating the lives of the wrongly convicted, false identification can mean real criminals go free. So kudos to Baltimore police and prosecutors for admitting past mistakes and taking steps to ensure they won’t happen again.

Baltimore joins just a handful of cities across the country that conduct sequential double-blind lineups. Even though there is overwhelming evidence that the practice reduces error, police associations and district attorneys often oppose attempts to adopt double-blind lineups. In California, for instance, former Governor Arnold Schwarzenegger vetoed lineup reforms after law enforcement agencies objected.  

According to the Innocence Project, Dallas, Minneapolis, Boston, Philadelphia, San Diego, San Francisco, Tucson, and Denver conduct double-blind lineups—as do police in New Jersey, North Carolina, and Connecticut.

Baltimore police have also begun to record interrogations, starting with cases involving serious crimes. See this Reason Foundation paper by Roger Koppl for more reforms that would improve the criminal justice system.