[caption id="attachment_19384" align="alignleft" width="300"] left to right: States Attorney Gregg Bernstein, Rebecca Brown – Director of State Policy Reform, Innocence Project, Police Commissioner Anthony Batts and Michele Nethercrott – Head of the Innocence Project at the University of Baltimore Law School[/caption]Baltimore police held a press conference Friday to announce a policy change that most people will never experience, but which could profoundly affect the prospects of those suspected of crimes in the city.Called the "Double-blind/sequential photographic array procedures," the new policy, contained in General Order J-9, upends decades of policy on how to present potential suspects for witness identification.In the old system, a detective working a case would sit the witness down and show a "six-pack"—a page with six photographs of people's faces on it. One of the pictures would be of the person the detective thought committed the crime; the others were fillers—people who look something like the suspect but aren't.In the new system, the detective working the case goes away and a different police officer brings six folders to the witness, each folder containing two pictures of a potential suspect or a filler."It removes any biases that may occur," said Deputy Commissioner John Skinner of the Investigations and Intelligence Bureau.Rebecca Brown, Director of State Policy Reform for the Innocence Project, a non-profit dedicated to freeing those falsely convicted of crimes, says 73 percent of the people exonerated by DNA evidence had been convicted because of at least one misidentification by a witness looking at a photo array.Psychologists and other criminal justice experts have noted problems with the "six-pack" arrays for decades, said Commissioner Anthony Batts, who says he has authored a paper on the subject that is about to be published. The double-blind method had been advocated sine the late 1980s, but few police departments have taken it up as policy. Batts calls it "an extraordinarily progressive technique" that he has worked to implement since his arrival last summer. Baltimore, he says, is both the only department using the technique in Maryland and the largest police department in the nation so far to adopt it.Batts thanked Michele Nethercott of the Innocence Project for help in "educating" the department. Nethercott says Maryland's experience mirrors the national trend—of nine exonerations in this state, seven involved mistaken identification by witnesses."We all have a shared interest in the reliability and integrity of evidence," Nethercott says.Among the cases Nethercott handled was Demetrius Smith, convicted in 2010 for a murder he did not commit and freed earlier this year. Two witnesses claimed Smith shot Robert Long in the head, and one of those witnesses claimed he had sold drugs for Smith in the past. It is unclear how the other one came forward to falsely identify Smith.Batts says his department works to analyze and correct mistakes made in false arrests and convictions "every single day," but acknowledges "we don't have a robust knowledge base" from which to make these corrections."We're building public trust," Batts says. "We're doing things based on science. Good science."