The use and accuracy of composite police sketches of crime suspects remains a hotly debated topic, says the New Orleans Times-Picayune. Several studies have shown sketches are unreliable when it comes to identifying suspects, and many academics have decried their use. Most police departments, including New Orleans’, still see them as a valuable tool. New Orleans Deputy Chief Kirk Bouyelas said, “It’s not the be-all, end-all, but some of these cases would never be solved if it wasn’t for these composites.”
Police use of composite sketches has evolved from a pen-and-pencil drawing to a sophisticated computer program that shades and stretches and tweaks features to reflect the memory of a witness or victim. In a study completed last year, three university researchers showed nearly 400 college students 12 police sketches of suspects — some computerized, some hand-drawn — alongside a photograph of the suspect’s face. They were asked if the two images depicted the same person. Overall, the students said 70 percent of the time that the sketches were not of the same person. American University Prof. John Watson, one of the researchers, called police sketches “highly suspect.” The biggest x-factor in whether a sketch is going to be helpful or harmful is the reliability of the victim’s memory, which is often difficult to gauge. Watson said witnesses are under stress during a crime, and emotion makes it hard to nail down important facial details.