The world recently lost it’s sh*t over a Netflix documentary called “Making a Murderer”.

The show begins with footage from a real criminal case, where a man named Steven Avery is released after spending 18 years in prison for a sex crime which he did not commit. Shortly after his release, Steven Avery finds himself in a new turmoil of accusations that implicate him in the murder of photographer Teresa Halbach.

One of the main pieces of evidence in the murder case is a confession by his 16-year-old nephew Brendan Dassey. Brendan Dassey claimed that he had helped his uncle rape and kill the victim. The account was extremely detailed, saying where and how Teresa Halbach was killed, and how the body was disposed of. Brendan Dassey later recanted his confession.

When his mom asked him why he would falsely confess to such a heinous crime, the following conversation was recorded (conversation is shortened, see original here):

Brendan: Well, you know I'm telling you the truth that it's not true.

Barb: Then why say it? …

Brendan: They said that they knew already what happened. That they wanted me to... They just wanted it coming out of my mouth.

Barb: But what I can't figure out is why you said all this shit if it's not true? And how you came up with it?

Brendan: Guessing.

Barb: What do you mean, "guessing"?

Brendan: I guessed.

Barb: You don't guess with something like that, Brendan.

Much of Making a Murderer goes on to explore whether or not his confession is accurate, and how it could have arisen.

My inbox has been flooded by friends and colleagues telling me you need to watch this, because this is totally what you research, and they are right. Along with many colleagues in the area of forensic psychology, I do research in order to try to prevent false confessions.

So, here is a crash course on the science of making a murder memory.

Why the Innocent Confess

There are three main reasons why people confess to crimes they did not commit.

The first is that they are voluntarily giving a false confession. Sometimes people confess to crimes because they want notoriety or they want to cover for someone else. For example, a gang member may confess to a crime committed by a higher-ranking gangster. They may also lie by admitting to a lesser crime than the one they are being charged with. Confess to a robbery and avoid a murder charge, for example. It’s a sneaky but effective way of creating an alibi.

The second is that they are being compliant. They are going along with the situation and are giving the interrogator what they think he or she wants to hear. They are guessing, like Brendan claims he did. Since police are keen on closing cases, they generally want to hear a confession. The thing with compliant confessions is that the person might say they committed a crime but might not actually believe it. Why might someone be compliant? They might be overwhelmed by the situation and want to escape it as soon as possible. One easy way to escape a hard line of questioning is to confess.

Third, they may have difficulty separating fact from fiction. This means that people can come to actually believe they committed a crime they did not commit, and they might even say they remember it happening. This is called a false memory of crime. These memories can be incredibly richly detailed, and the person may come to believe a story presented to them through problematic police interview techniques. This type of confession is called internalized, because the person accepts the event as part of their personal past.

How to Make a Murder Memory

Making a Murderer digs deep into the problematic police assumptions and strategies that may help to generate a false confession. What the show does not explore is how, after you get an initial statement from your suspect, you can also make them believe it. This is what I do in my own research, in which 70% of participants have told me all about how they committed crimes (assault, assault with a weapon, and theft) that never happened. Here’s how it works:

Step 1: Introduce what scientists call “misinformation”, by telling a person they did something they didn’t. This will be more convincing if you have authority and claim to have evidence.

Step 2: When they dispute your accusation, saying something like I didn’t do that, refute it. Of course you did. Just tell the truth.

Step 3: Offer to help them remember. Get them to imagine what the crime could have been like. This leads to something called “imagination inflation,”,where picturing things happening forms the foundation for a belief they actually did happen.

This is where Making a Murderer stops. They obtain a confession from Brendan and stop badgering him. In other cases, however, the police may want a more complete confession, one that the suspect fully accepts as the truth. In such cases we find ourselves at the next steps, where the suspect can go from being compliant to genuinely believing a false memory.

Step 4: Keep insisting they did it, and keep having them try to imagine it. Try to get them to picture the details. Why did they do it? Where? When? How did it feel? When they recall anything, reinforce it. Say something like it sounds like the memory is really coming back. It’s great that you are telling the truth.

Step 5: Reap full false memory, and record the person confessing in vivid detail how they committed a crime that never happened. At this point, the suspect actually believes they committed the crime.

World experts on false confessions, including Saul Kassin and Richard Leo, claim that the resulting confessions can lead to wrongful imprisonment due to a cascade of errors which follows, where other forms of evidence are tainted. Police and forensics teams may find themselves with tunnel vision, ignoring evidence that shows their suspect is innocent.

Only the Vulnerable?

In Making a Murderer, Brendan Massey is a vulnerable 16-year old with a low IQ who appears to have been pressured into giving a confession.

It may be easy to see why someone who is low functioning could generate a false confession. While people who falsely confess in criminal cases are disproportionately likely to be vulnerable, it is likely that most people will falsely confess if given the right circumstances.

According to the Innocence Project, a whopping 25% of all wrongful convictions involve false confessions or incriminating statements. Most of these people are adults, and have an IQ well within the normal range. Making people confess to things they didn’t do is easier than we might be happy to accept.

Final Thoughts

Next time you think about how different you are from Brendan in Making a Murderer, realize that you too could find yourself in a situation where you are at risk for confessing to a crime you didn’t commit.

Realize also that by knowing about false memories and false confessions, you are probably more able to protect yourself from the police memory hacking you. More specifically, if you are innocent and are questioned by the police, refrain from going along with suggesions to imagine “what if” exercises, and be very cautious when disclosing anything.

Now that you know, I release you to head back to world of entertainment to find the next viral crime sensation.

This post is part of a series of articles that focus on debunking common misconceptions and beliefs about how our memory works.