Scanning a defendant’s brain can establish mens rea, claim neuroscientists

Will the results be used in the courtroom?

A group of top neuroscientists is claiming that the mens rea of a crime could be established by scanning a defendant’s brain.

Cue the terrible flashbacks to criminal law lectures: Latin for “guilty mind,” the mens rea of a criminal offence is its mental element. Different offences carry different levels of mens rea, so the court will sometimes need to consider whether a defendant committed a crime on purpose, through sheer reckless behaviour, accidentally, etc.

Researchers — based both in the United Kingdom and the United States — scanned the brains of 40 volunteers as they took part in a computer-based task that required them to smuggle a suitcase across the border of a country. Offered a reward for doing so, some participants were told that the suitcase contained drugs, while others were not. The computer simulation also varied the risk of the volunteers being stopped and searched at customs.

Brain scan images taken from participants

With the would-be smugglers undergoing brain scans as they carried out the online tests, scientists claim that they were able to establish — with a high-degree of accuracy — which participants were knowingly breaking the law, compared to those who were simply taking a risk.

Commenting on the significance of the research, the paper states:

Because criminal statutes demand it, juries often must assess criminal intent by determining which of two legally defined mental states a defendant was in when committing a crime. For instance, did the defendant know he was carrying drugs, or was he merely aware of a risk that he was? Legal scholars have debated whether that conceptual distinction, drawn by law, mapped meaningfully onto any psychological reality.

But criminal lawyers do not need to panic just yet. Taking a more sceptical view of the research’s implications, anonymous blogger the Secret Barrister told Legal Cheek:

While it’s interesting that there appears to be a neurological distinction between intent and recklessness, it’s doubtful that this will be of any practical significance in the courtroom for juries assessing past events.

There is also one major snagging point. “In most cases, when someone is committing a crime they are not doing so while inside a scanner,” the paper concedes.

Read the research paper in full below:

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As lie detector test results are not used in criminal trials neither will we see brain scans.


But if the research essentially demonstrates that knowledge of wrongdoing can be reliably assessed by looking at particular activity in the brain, the technology could presumably offer a lie detector that works.

At present lie detectors only record external symptoms of stress – presumed to come from the knowledge of lying – and which can be overcome or be frustrated by techniques to increase stress signals when answering uncontentious questions. Brain scans could by-pass that problem.

I expect evidence based on this sort of technology will be commonplace in a decade or two, at least in bigger trials.


You are full of shit, and you and these neuroscientists need to be kept as far away from the criminal justice system as possible. The research demonstrates nothing more than what happens in an experiment where the “perp” is aware they are involved in a staged experiment and are hooked up to equipment as they are doing. Even if this experiment was repeated on a 1000x bigger scale, the findings are equally worthless, because they only repeat the same artificial experiment on a bigger scale. And befor anyone comes back with MUH JURIES ARE FALLIBLE, that is no reason to add an extra layer of fallibility to the fact finding process.


My my, aren’t you a confident little boy.

But it’s time you got back to the overdue essay or whatever it is that you should be doing on your course and left the grown-ups to chat.


Too right, I’ll let you get on with your science fiction wank-fest.


Completely agree with Trumpenkrieg

Frightening how much trust people place in technology really


In nearly all cases, AR + MR has to coincide at the actual time the offence was committed….

Cant do a scan retrospectively after a period of time has elapsed to establish MR….


Sounds like truly dangerous bullsh1t to me, but no doubt Susskind will get super excited about it even though there are glaringly obvious drawbacks.

Just Anonymous

‘There is also one major snagging point. “In most cases, when someone is committing a crime they are not doing so while inside a scanner,” the paper concedes’

Yes, that is a rather fundamental problem!


A related question, will a neurological state that causes or indicates a propensity to commit crime amount to a defence?


Public policy; because mens rea in English law is ugly and awkward enough in its conception and cannot be changed radically without codification, for which there is no desire; because law is always behind science; because one should resist their urges if they know the consequences are illegal and/or morally wrong (i.e. paedophiles).


Why is anyone giving this idea credibility?

It’s basically proposing the integration of ‘thought-crime’ into English law.


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