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The mind of a serial killer

There are a number of murders that have shocked the country, the most recent being the ones committed by Masten Wanjala. But do these killers qualify to be called serial killers? What makes a serial killer?


June 30, 2021.

The day Mr Tony Opindo, 42, will painfully live to remember.

That evening, the father of four thoroughly enjoyed an evening conversation with his son Charles Opindo Bala, 13. Little did he know it would be the last time he would be seeing his son.  

“Three days later, I received a call and the person told me not to bother looking for my son. He seemed to derive amusement and pleasure in torturing me psychologically and emotionally. I could not eat or sleep.

He asked me to send him Sh30,000 if I wanted to see my boy alive. I then involved the police who started tracing the call. 

He called again two days later, demanding for Sh2,000 saying he was broke. I sent him the money. He called once again after three days demanding another Sh2,000, which I sent ,” Mr Opindo narrated.

He was shocked to learn that his tormentor is someone he knows and has been interacting with.

“I have met him in the football field in Majengo where we live on numerous occasions because he loved playing football. I never knew he was silently observing me, my son and my life so that he hits where it hurts me the most. My son is gone and I will never see him again, but the pain is not as much as not knowing where he is. I leave it to God,” he says while holding back his tears.


That is the official number of children brutally murdered by Masten Milimu Wanjala, 20, who hails from Bungoma County. This is as per police reports last week. The revelation left social media awash with terms like vampire, devil-worshipper and serial killer.

Masten Milimu Wanjala

Masten Milimu Wanjala at the Makadara Law Courts in Nairobi on July 15, 2021.

Photo credit: Dennis Onsongo | Nation Media Group

It is the disappearance of two boys in Shauri Moyo that led detectives who had been on his trail for weeks to the suspect – he was linked to the kidnapping of Charles Opindo Bala, 13, and Junior Mutuku Musyoka, 12.

But this is not the first time cases of such bizarre killings have been reported in Kenya.

Past killings

In 2008 police rescued two women in Naivasha’s Kihoto slums who claimed they had been kidnapped, raped and drugged by an unknown stranger who was later identified as Geoffrey Matheri alias Fungo. They said he drained and drank their blood as they watched.

The police later exhumed the body of a woman with some of her body parts missing from a shallow grave in his mud house.

In the same town, Philip Ondari Onyancha, in 2009, confessed that he had killed 18 women.

He then narrated how he had been recruited into a cult while at school by a teacher who asked him to kill 100 people and drink their blood for good fortune.

Phillip Onyancha (in sweater) leads a security team to a hotel in Nakuru Town where he claimed to have killed a woman.

In Shinyalu, Kakamega County, in the year 2000, Jamin Mukhobero Muchika slaughtered eight members of his own family, including his pregnant wife.

Mukhobero then lured neighbours to his home where he attacked them before opting for an unsuccessful suicide attempt.

Early this year, Lawrence Warunge, 22, confessed to killing his father, mother, brother, cousin and a farmhand employed by the family.

The Mount Kenya University student who stabbed his own father 34 times before slitting his throat told homicide detectives that Killing Eve, a British dark comedy-drama TV series inspired him to commit the cold-blooded killings.

Kiambu murder suspect Lawrence Warunge

Detectives escort Lawrence Njoroge Warunge (centre) out of the Kiambu Law Courts on January 11, 2021.

Photo credit: File | Nation Media Group

Who is a serial killer?

The Federal Bureau of Investigations (FBI), defines serial killings as a series of three or more murders.

To be clear, serial killers murder in a period of over a month, with “cooling down” time between murders.

For them, the murders must be separate events, which are most often driven by a psychological thrill or pleasure.

They often lack empathy and guilt, and most often become egocentric individuals; these characteristics classify certain serial killers as psychopaths.

Serial killers often employ a “mask of sanity” to hide their true psychopathic tendencies and appear normal, even charming, according to psychologists.

In the US, a famous serial killer, Ted Bundy, would fake an injury to appear harmless to his victims. Experts categorise him as an organised serial killer since he methodically planned out his murders and generally stalked his victim for several weeks before committing the crime.

Mr Bundy committed an estimated thirty murders from 1974 to1978 before his eventual capture.

Troubled Family

Speaking to Healthy Nation, Mr Wanjala’s father, Robert Watira from Namakhele in Bungoma County, said he does not know his son well enough to ascertain whether he had been having any mental health struggles.

“As a father, I am not party to his current predicament. I tried to give him a better life but he chose to flee, I only know that he loves to play football and keeps to himself mostly.  He now must carry his own cross,” Mr Watira said.

His marriage with Wanjala’s mother, Edna Nabalayo, was not a bed of roses as they separated before the child was born.

“I honestly lost touch with her completely and have been separated for a very long time. The boy was brought to me at 17 years of age, I don’t know him well enough, but I know she is married to someone else in Machakos,” he added.

Last year, Wanjala’s step-sister, Gladys Wanjala, came home with horrifying reports. She told their father that her little brother was suspected of killing a child in Machakos and was on the run, hiding at his father’s home.

“When he came home and found his sister, he disappeared fearing that he had been exposed and I have never seen to date,” Mr Watira disclosed.

North Bukusu sub-location (where Mr Wanjala comes from) chief Boniface Nbieyira is of the opinion that the lack of mental health treatment facilities and rehabilitation centres in the area could be the reason a young man could do such a thing.

“I know and have interacted with the boy, he was a good boy, he loved playing football but we are shocked as a community because we have never had a person from our area do this. He must have learnt it in Machakos where he went to stay with the mother,” the local administrator said.

While reacting to the devastating news, United Nations Children’s Fund (Unicef) Representative to Kenya Maniza Zaman condemned the kidnapping and murder of children in Nairobi and other parts of Kenya in an official statement that called for those responsible to be held to account.

“Unicef condemns in the strongest possible terms the kidnapping and killing of children – this is one of the worst crimes imaginable and there can be no excuses for it. We need to redouble our efforts to ensure that children are protected wherever they are – at home, in schools and in public spaces,” she said.

She added: “We need psychosocial support for child victims and their families, and we need to ensure that the public is vigilant and knows how to recognise and report any kind of violence against children.” 


Dr Gathoni Mbugua, a wellness therapist and clinical psychologist at Chiromo Hospital in Nairobi says Mr Wanjala’s behaviour might be based on interactions during his formative years, that is, between zero and 10 years.

“When a child is born we have what we call tabula rasa. It’s a blank slate, and their environment contributes to at least 70 per cent of who they turn out to be. That is why even if you are born in a space of resources but your environment was traumatic it won’t matter,” she said.

The expert further explained that from the age at which a child experiences trauma, they do not grow and can get stuck at that point.

“The things that happen in formative years of childhood, and here we are talking about adverse childhood experiences, result in what we are seeing now.  Clinically, the question should be: what happened? If the traumatic experience comes say at nine years, a child will get stuck there psychologically, emotionally and mentally but grow physically,” she explained

However, she said, it is rare for a serial killer to target children.

“Unless they are either trying to relive a moment or revenge a particular thing that could have happened when they were at a particular age,” she said.

“The impact of the separation between his parents should be studied. How did the mum remarry? How was he treated in his new home?

“Did he find maybe another boy in his new home who could have caused him trauma? Now that he is in a position of ‘power’ he could be reliving that moment in a bid to, this time round, ‘defend’ himself’. 

“You see, this is how the brain operates.  The young man might be putting himself in a similar situation because he imagines that this time round he is going to be capable of protecting himself, only that he can’t,” Dr Mbugua explained.

This is to mean that his moral compass is broken and therefore he cannot rationalise and separate between good and bad.

Dr Mbugua stressed that Mr Wanjala needs to be assed properly for experts to determine the type of mental illness he has, but she is of the opinion that there are compelling indicators that the suspect is a mental health patient.

“For example, if he is hearing  voices like schizophrenics do, he sees young boys as a threat and the ‘ command voice’ tells him to kill but now we do not know for sure because he has not been properly assessed,” she said. “He has no conscience and that lack of a conscience is what psychopathic tendencies are and that’s what actually makes a serial killer.”


According to Crime Museum, a global organisation that documents crime, though identifying a future serial killer is not an exact science, there are a few signs that may help to identify people who have the greatest potential to become serial killers.

“These traits can typically foreshadow the violent activities the killers engage in later in life but are not linked directly to serial behaviour.

“Extreme antisocial behaviour is one possible indicator that an individual may have a problem, but it is by no means definitive. Antisocial personality disorder is a personality disorder, defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, as someone who shows no remorse or guilt.

“Other signs that one suffers from antisocial disorder include patterns of lying, aggressiveness, failure to conform to social norms, and irresponsibility,” the organisation notes.

Another common indicator of possible serial killing behaviour is cruelty to animals.

“They may provoke, torture, or even kill cats, dogs and other animals. Even after seeing the results of their actions, the person will show no form of regret or remorse. Serial killers generally seek control over the life of another, and at a younger age, a small animal is easiest to fully dominate.

“Any adolescent who displays this activity is at an extreme risk of developing into a serial killer when they reach adulthood,” the crime experts say.

Dr Michael Stone, a professor of psychiatry at Columbia University, however, notes that there is a difference between serial killers and mass murderers.

 “Mass murderers kill many people, typically at the same time in a single location. With some exceptions, many mass murders end with the death of the perpetrators, either by self-infliction or by law enforcement.

“Mass murderers are generally dissatisfied people, and have poor social skills and few friends. Generally, the motives of mass murderers are less obvious than those of serial killers,” he believes. 

According to Dr Stone, 96.5 per cent of mass murderers are male and most of them are not clinically psychotic.

Rather than being a psychopath like most serial killers, mass murderers tend to be paranoid individuals with acute behavioural or social disorders.

 Like serial killers, mass murderers also display psychopathic tendencies, such as being cruel, manipulative and uncompassionate.

However, most mass murderers are social misfits or loners who are triggered by some uncontrollable event.

Serial killers and mass murderers often display the same characteristics of manipulation and lack of empathy.

What differentiates the two is the timing and the number of the murders.

Serial killers commit murder over a long period of time, and often in different places, while mass murderers kill within a single location and time-frame.

Dr Mbugua explained that when police officers are quick to declare and brand an individual they have arrested in connection to a series of murders ‘a serial killer’, without comprehensive clinical tests and analysis, it is unfair. 

“Once they say that somebody is a serial killer, they live permanently with that tag and it prevents them from getting proper treatment or even justice since you have already passed a verdict and found them guilty. Maybe he has serial killer tendencies but you can only be sure after proper assessment,” she said.

“For one to be a serial killer, there should also be a pattern which is not just numbers, say three, four or five murders. 

“Clinically speaking, there is a criteria you must meet, we look at the style of killing, like hanging, hacking or strangling in a particular format, stalking or tying their victims in a specific manner,” Dr Mbugua explained.

While dissecting the notable “serial killer” cases we have had in Kenya in the past, Dr Mbugua believes that they are all behaviourally connected.

“Yes, because number one, you know we call it murder because they are premeditated. All these cases were meticulously planned by each of the individuals.

“It also seems the psychopathic tendencies are more dominant in men but to fully establish this we need to get their full histories and establish the exact point that made them ‘cross over’. There’s research that shows that many of the murders are as a result of some form of addiction,” she noted.

Dr Mbugua further interrogated reports that the killers usually allege needing human blood for sacrifice or they are drinking it as some form of initiation.

“The blood or need for blood for satanic or demonic rituals   emanates from our religious and cultural beliefs as Africans and the fact that we are heavily bound by them.

“As Africans, for many years, the things we cannot comprehend we usually attribute to witchcraft or demonic practices.   People show psychopathic traits in our community but no one wants to believe it, we try to pray for them or ‘offer sacrifices’ and interestingly even the most educated are deeply embedded into such belief systems,” Dr Mbugua explained.

She wished our police officers would rethink their approach to “serial killer confessions”.

“In the legal sense, for a confession to take place, there is a structure in place and even a lawyer has to be present. We live in a culture where people are threatened and pressured to confess and it does not usually weigh into the impact of what they are saying.

 “We need to use irrefutable evidence like DNA to link the killers to each of these bodies before jumping to conclusions, especially because the media is such a powerful tool and like I said, once the tags and labels are up, the suspect and his family have to live with them forever,” she said. 


Currently, according to the Kenya Mental Health Action Plan 2021-2025, there is inadequate data and information on the prevalence of mental health problems, neurological and substance use.

However, it is estimated that up to 25 per cent of outpatients and up to 40 per cent of in-patients in health facilities suffer from mental conditions.

The probable prevalence of psychosis in Kenya is about 1 per cent of the population.

The most frequent diagnoses of mental illnesses made in general hospital settings are depression, substance abuse, stress and anxiety disorders.

Commonly reported traumatic events such as violence, disasters and conflicts, as well as unemployment and poverty, may play a significant role in the growing trends of post-traumatic disorders, anxiety, depression and suicide among those affected.

Furthermore, the mental health task force report pointed out the perennial non-prioritisation of mental health policy implementation at national, county and community levels is a major hindrance to mental health service provision in the country.

The Mental Health Act, enacted in 1989, the report further noted, requires amendment to align it to the constitution and address emerging issues. Other legislations were found to have clauses that negatively impacted on people with mental health conditions, psychosocial, intellectual and cognitive disabilities.

The action plan notes that the number of multidisciplinary mental health professionals in the country is low compared to the service need while many qualified professionals are unemployed.

“The system of forensic psychiatric services is dysfunctional, with many people with mental health conditions not accessing healthcare services, fair administration of justice and fulfilment of their human rights,” it further states.

In Kenya, only 0.01 per cent of the national health budget is allocated to mental health according to the plan. The amount of money that ought to be spent on mental health is Sh250 per capita, yet the country is spending only 15 cents.

The National Hospital Insurance Fund cover is not comprehensive, while private insurance policies tend to be discriminatory.

This means that many Kenyans are pushed into poverty due to out-of-pocket payment for mental healthcare or go without care, with devastating consequences.