Then the landscape changed. In New York in 1992, attorneys Peter Neufeld and Barry Scheck founded the Innocence Project, a nonprofit organization that used new DNA technology to examine prisoners’ claims of innocence. As the DNA exonerations started to pour in (a number that is now up to 374 and counting), they revealed that over 28 percent had involved a false confession. In the subset of homicide cases, that percentage was doubled.

At about the same time, scientific research on false confessions started to identify vulnerable suspect populations (like teenagers, and adults with intellectual disabilities and mental health issues), psychologically coercive tactics (like lying about evidence and implying leniency upon confession), and other risk factors — like the fact that innocent people almost never lawyer up (“Why would I, I didn’t do anything wrong!”).

The problem is not just that innocent people can be broken into capitulation; it’s that their narratives are often too compelling to disbelieve. When law professor Brandon Garrett analyzed 66 false confessions, he unearthed this startling fact: Most contained details about the crime that were spot-on accurate, often vividly so, and yet not known to the public. These confessors were all innocent; they didn’t know firsthand what happened. Whether purposeful or inadvertent, the detectives in these cases had communicated the facts during the interrogations — a process known as “contamination.”

A retired Washington, D.C., detective, James Trainum, knows all too well how this can happen. In an article titled, “I took a false confession — so don’t tell me it doesn’t happen!” Trainum reflected on a case in which a suspect who confessed to him was later exonerated: “Years later, during a review of the videotapes,” he noted that he and his colleagues had “discovered our mistake.” He explained: “We showed the suspect our evidence, and unintentionally fed her details that she was able to parrot back to us at a later time. It was a classic false confession case and without the video we would never have known.”

Inspired by these developments, many professional organizations — like the International Association of Chiefs of Police — have called for the video recording of custodial interrogations. Twenty-five states, the District of Columbia, and all federal law enforcement agencies also went on to adopt the practice for some or all felonies.

Every agency should demand the recording of all suspect interviews and interrogations without exception.

As reported in the American Criminal Law Review, Tom Sullivan, a former United States attorney and partner at Jenner & Block in Chicago, interviewed hundreds of officers in police and sheriff’s departments that had begun to record interrogations. Almost to a person, these officers became “enthusiastic supporters.”