Why Would an Innocent Person Confess?

You are certain you would never confess to something you did not do. Everybody is.

Of the people cleared by DNA evidence after a conviction, about a quarter had confessed. They were not beaten. They sat in a room and said they did it. Some described the crime in detail, using facts that had been mentioned to them earlier in that same room.

Your certainty is part of how it happens.

The room

The room is small and bare. There is no clock, because losing track of time is part of the method. You sit furthest from the door. None of that is illegal, and none of it is an accident.

The technique used across much of the English-speaking world was designed in the 1950s to replace beating people. It was a real improvement on what came before.

A judgment made by eye

It begins with a friendly interview to decide whether you are lying. If the interviewer decides you are, everything after that assumes guilt.

People are measurably bad at detecting lies by eye. Trained investigators score close to chance. Training raises confidence sharply. It does not raise accuracy.

Two levers

Maximisation. The case against you is overwhelming. Your prints are there. A witness saw you. None of it has to be true. In many countries, including the United States, interviewers may lawfully claim to have evidence they do not have.

Minimisation. The interviewer becomes sympathetic. Anyone would have done it. It got out of hand. This is not a promise of leniency. It only sounds like one.

Then two versions are offered. You are a monster who planned it, or you are a person who snapped. Both are confessions. Nobody offers the third door, which is that you were not there.

Time does the work

• Most true confessions come within about two hours.
• Most false confessions come after six hours, and many after sixteen.

Guilty people tend to give up early. Innocent people keep explaining. What is being worn down is not honesty. It is the ability to keep deciding things.

Sleep loss matters a great deal. In a laboratory test, one night without sleep made people several times more likely to sign a statement admitting to something they had not done.

At some point the goal changes from proving innocence to making it stop.

The keyboard experiment

Students were asked to type and told not to press one key, because it would crash the computer. A minute in, the computer crashed on its own. Every student denied pressing the key, because every student was innocent.

Then a second person said they had seen it happen.

Most students signed a confession. A large share came to believe they had done it, and some invented memories of their finger slipping. There were no threats, and it took under an hour.

After the confession

A confession is the most powerful evidence there is. Once one exists, other evidence starts to be read to fit it. Uncertain witnesses become certain.

Juries convict at high rates even when told the confession was coerced. Often only the confession was recorded, so the jury sees a calm person explaining and never sees the hours before.

This is a solved problem

Record the whole interrogation from the first minute. Where that is required, false confessions fall, and so do arguments about what was said.

Several countries replaced the method altogether. The newer approach tries to get an account, not a confession. The person talks at length and the account is checked afterwards. Forces that adopted it did not solve fewer crimes.

Four words

Lawyers agree on one sentence: I want a lawyer.

Most people waive that right, and innocent people do so more often than guilty ones, because they believe that having done nothing will be obvious if they just explain.

Asking for a lawyer is not an admission. It is what the right is for.

The short answer

Innocent people confess because a guess made in the first minutes is never revisited, because the evidence they are told about may not exist, and because hours without sleep make anybody worse at deciding. The four words are for you, not only for somebody guilty.