What is Neurolaw? 

Neurolaw is an interdisciplinary field that links the brain to law. It facilitates the  pathway to a better understanding of human behaviour in order to regulate it  accurately through incorporating neuroscience achievements in legal studies. 

Neurolaw is an emerging field that is capable of revolutionising the law. The  study of the brain and its relation to criminal behaviour helps to understand the  neuroanatomy of violence. This enables to detection of hidden bias, detection of  lies and prediction of future criminal behaviour. Neurolaw has an importance of  its own in deciding a case pertaining to violent crime. 

This article, inside a murderous mind: Emergence of neurolaw, explores the  various aspects of the neuroanatomy of violence and criminal behaviour. It also  takes into account the instances where neurolaw was applied in courtrooms  while deciding a case of violent crime. 


Do our primitive hearts still seek the thrill of the combat drums?  Consider the following scenarios:  

1. Cheering as one boxer wins in the ring.  

2. Hailing cries of victory after winning a war.  

Western society has its definition to justify these acts. We love boxing! War  was needed to protect the nation from greater harm. As rightly quoted by Adrian  Raine in The Anatomy of Violence: “Something attracts us to violence.” 

Some parts of our evolutionary backgrounds persist till today. The adaptive  nature of basic instincts explains our attraction to violence. During the ancient  days, it was a matter of survival and strength. Today, the very nature has  evolved to take the shape of crime. Men generally gathered to conduct killings  in other villages to gain power and resources. There isn’t a single instance  where women have banded together to expand the territory or seek power. In  comparison to the present day, for every one female murderer, there are nine  male murderers. 

Moving on from the evolutionary aspects of crime, the biological makeup  contributes to violence. The brain is the body’s control centre. Its function  ranges from governing body movements to emotional control. Why don’t we all  have the urge to kill? What makes a killer different from the rest?  

We must remember that 99.9% of the time, murderers are common people who  blend in the society just like we all do. Tragic incidents and impulsive actions in  a matter of seconds are what sets them apart. Added to this is the neuroanatomy  of violence.  


Before we begin, note that there are two types of killers. One, killers who  calculate every step and are rarely under any suspicion. The serial killers. The  second type is the impulse-driven killers who commit such acts on a whim.  Their actions are unplanned and reckless. The criminal acts fall under the same  umbrella irrespective of the kind. But, brain functioning is different for each  category. How is the brain related to violence? 

It is noted that damage to the prefrontal area of the brain or poor prefrontal  performance is associated with a predisposition to violence. Impairment of the  prefrontal cortex is described at different levels below:  

1. Emotional Level: The reduced functioning of the prefrontal cortex results  in the loss of evolutionary, primitive parts of the brain. One such part is  the limbic system that generates raw emotions like rage and anger. When  the prefrontal cortex is functioning well, these emotions are kept in  check. In case of dysfunction, these emotions are not regulated.  

2. Behavioural Level: Damage to the prefrontal cortex can result in risk taking, irresponsible and rule-breaking behaviour. It won’t take long for  these behaviours to turn into violent behaviour.  

3. Personality Level: The prefrontal damage also results in personality  changes like impulsivity, loss of self-control and inability to modify and  inhibit behaviour appropriately.  

4. Cognitive Level: Poor prefrontal functioning leads to a loss of intellectual  flexibility and poorer problem-solving skills. This in turn results in failure  at school, unemployment that disposes a person towards violent ways of  life.  

5. Social Level: With poor social skills, lack of judgement, immaturity due  to prefrontal damage; paves the way to socially inappropriate behaviour  and poorer ability to formulate non-aggressive solutions to social  encounters.  

https://medium.com/writers-blokke/inside-the-brain-of-a-murderer 5e171291b878

Case Study 

For better understanding, let’s take the case of two murderers.  

Antonio Bustamante, who impulsively killed an old man during a botched  robbery. Motivated by greed and money, he committed the offence on his  impulses. He had a criminal record of theft, breaking and entering and drug  offences. He was a recidivistic criminal, a typical thug. It was discovered that at  the age of twenty he had suffered a head injury from a crowbar. His personality  changed after that injury. He transformed from being a well-regulated  individual to a recklessly impulsive criminal. Bustamante suffered a dysfunction  in the prefrontal cortex.  

An exception to poor prefrontal functioning is Randy Kraft – the scorecard  killer. He killed approximately sixty-four people in a span of twelve years  without getting caught. You need good prefrontal functioning to pull that off.  He had an excellent ability to plan, regulate his actions, think ahead and  consider alternate plans of action. He had no previous criminal records.  

Proactive and Reactive aggression 

This leads to the categorisation of aggression into proactive aggression and  reactive aggression.  

Proactive aggression: Predatory people use violence to get what they want in life. They plan ahead and display regulated and controlled behaviour. Rewards that are either external and material or internal and psychological are the driving force for this category. Cold-blooded and dispassionate are the traits of predatory killers. Serial killers like Randy  Kraft fall into this category.  

Reactive aggression: They lash out emotionally on proactive stimuli. For  instance, they hit back in anger if called names. They are emotional and  unregulated. Murderers like Antonio Bustamante fit into this category.  

If predatory killers have normal prefrontal functioning, what makes them killers  in the first place? 

Both murder groups (proactive and reactive) showed higher activation in the  subcortical limbic regions. The limbic system is a site of emotions. It is partly  responsible for deep-seated aggression and rage which both the groups have in  common. The difference, however, is that cold-blooded killers have sufficient  prefrontal regulatory resources to act on their aggression. They respond in a  relatively careful premeditated fashion. Despite all the planning, serial killers  unleash their emotions in a fury that leads to unregulated killings. On the other  hand, hot-blooded killers don’t have sufficient prefrontal regulation to express  their anger in a controlled manner.  


Imagine committing a crime that benefits you but brings harm to others. Just the  thought of it prickled you, let alone the actual commission and completion.  That’s your conscience. Conscience is predicated on the good functioning of  your autonomic nervous system. The autonomic nervous system plays a key  role in emotions. For some offenders, it confers on them a fearless risk-taking  conscience free personality that leads to psychopathic behaviour. This makes  them biologically different from the rest of us.  

The conscience that is made of gut actions and feelings generated in a part of  the autonomic nervous system gives a sense of right and wrong. The biosocial  theory comes into the picture to determine the sense of right and wrong. Lack of  fear conditioning results in underdeveloped conscience. This lack of conscience  makes the killers who they are.  



Heart rate is also an indicator of antisocial and violent behaviour. Antisocial  kids tend to have lower heart rates. Lower heart rate is thought to be associated  with lack of fear which is termed as the fearlessness theory. For instance, bomb  disposal experts have lower heart rates. It takes nerves of steel to deal with  bombs. And despite that, they function well as individuals in society.  

In the case of offenders, punishments like prison do not motivate them to reduce  their acts of violence since the punishment does not hold fear to them. With a  lower heart rate, empathy is equally low which is a common trait in most  murderers.  


Now that we have understood how the biological makeup can be responsible for  violent crimes, it is important to comprehend the role neuroscience has in a  courtroom. A 1990s case in the American legal system displayed the role of  neuroscience in deciding a case.  

Herbert Weinstein, a 65-year-old ad executive, strangled his wife. In an attempt  to make it look like suicide, he threw the body out of the window of their 12th floor apartment. In the brain scans, it was found that there was an abnormal cyst  (arachnoid cyst) that surrounds the brain like a spider web. It was decided that  Weinstein would plead guilty in exchange for a reduced charge of  manslaughter.  

The case of R v Peterson 

Mr Peterson was accused of murdering his friend by bludgeoning his head with  a table leg during a fight. Peterson was a man of limited intellectual ability and  the trial judge accepted that the deceased had started the fight (but rejected the  accused’s self-defence claim). Four experts – two psychiatrists and two clinical  neuropsychologists – gave evidence about Peterson’s mental condition. The  psychiatrists noted that Peterson suffered from two underlying conditions:  intellectual disability and “executive dysfunction caused by frontal lobe  damage.” 

This diagnosis of frontal lobe damage was made on the basis of a behavioural  assessment, and not any kind of brain scan. The experts explained that these  impairments affected the accused’s ability to control his behaviour and  understand the consequences of his actions. Justice Campbell accepted the  expert evidence and allowed the partial defence.

Neurolaw is an emerging field and bringing neuroscience to the courtroom is a  revolution of law. Neuroscientific evidence plays a role in reducing death  sentences to life imprisonment.  


Carter Snead, a law professor at Notre Dame gave a report titled Neuroscientific  evidence in criminal law for President Bush’s Council on Bioethics. The reports  conclude that there are a large number of cases in which such evidence is  presented is striking. Neuroscientific evidence questions guilt and punishment,  detection of lies, hidden bias, prediction of future criminal behaviour. However,  skeptics fear that this may threaten privacy and mental freedom as it involves  extensive research on the brain and its functioning. It brings in the concept of  cognitive liberty that is widely speculated by experts.  

On an ending note, here is a question to all the readers. Since all behaviour is  caused by our brains, wouldn’t it mean that all behaviour could be potentially  excused?  

Resources: The anatomy of violence written by Adrian Raine

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