The current issue of the Monitor has a short article on some new data regarding eyewitness testimony.  For many years, various psychological experts have insisted that sequential lineups are vastly superior to simultaneous lineups.  Now, perhaps, the reverse is true:

By some estimates, around a third of law enforcement agencies in the United States now use the sequential format, says John Wixted, PhD, a psychologist at the University of California, San Diego. But, he says, that switch might have been a mistake.

Wixted is one of several scientists, along with Clark and Scott Gronlund, PhD, a psychologist at the University of Oklahoma, who have championed a statistical method called receiver operating characteristic (ROC) analysis, a method widely used in other fields to measure the accuracy of diagnostic systems.

Using that analysis, sequential lineups don't appear to be beneficial -- and might lead to slightly more misidentifications than simultaneous lineups, Gronlund and Wixted have reported (Current Directions in Psychological Science, 2014). The problem, they say, is that previous analytical methods confounded accuracy with a witness's willingness to choose a suspect. In other words, sequential lineups seem to make people less likely to make a choice at all. But when they do pick a suspect, they might be at greater risk of making the wrong choice. "It turns out sequential lineups are inferior," says Wixted.

And what about eyewitness confidence?

For many years, researchers didn't think an eyewitness's confidence revealed much about his or her accuracy in identifying a suspect, says Wixted. A confident eyewitness could be just as likely to get the ID right -- or wrong -- as a less confident witness. But in the last two decades, numerous analyses have converged on the fact that eyewitness confidence is actually a strong indicator of accuracy.