One night in 1984, a man broke into 22-year-old Jennifer Thompson’s apartment, threatened her at knifepoint, and raped her. While it was happening she tried to memorize everything about him—his face, hair, clothes, body type. Later that day, she recounted those details to a police sketch artist.
Two days later, a detective showed Thompson a photo lineup of six men. She ruled out four of them right away, and stared at the other two pictures for four or five minutes. Finally she chose one. “Yeah. This is the one,” she said, as recounted in the book Picking Cotton. “I think this is the guy.”
“You ‘think’ that’s the guy?” one of the detectives asked her.
“It’s him,” she said.
“You’re sure?” asked another detective.
She wrote her initials and date on the back of the photo, then asked them, “Did I do OK?”
“You did great, Ms. Thompson.”
The man she identified, Ronald Cotton, was convicted and sentenced to a life in prison. More than 10 years later, a DNA test revealed that Thompson had pointed to the wrong guy. Cotton was innocent.
Eyewitness testimony is hugely influential in criminal cases. And yet, brain research has shown again and again that human memory is unreliable: Every time a memory is recalled it becomes vulnerable to change. Confirming feedback—such as a detective telling a witness she “did great”—seems to distort memories, making them feel more accurate with each recollection. Since the start of the Innocence Project 318 cases have been overturned thanks to DNA testing. Eyewitness mistakes played a part in nearly three-quarters of them.