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Joanna Dennehy: Bright and Bookish Schoolgirl who Grows up to Become a Serial Killer

Joanna Dennehy: Bright and Bookish Schoolgirl who Grows up to Become a Serial Killer

“I wonder if female serial killers haven’t been studied extensively because at the end of the day, in our heart of hearts, we don’t consider them worthy antagonists.” These words by Tori Telfer don’t hold against this lady killer named Joanna Dennehy who is a true antagonist in every man’s nightmare.

Joanna Dennehy, right alongside her partner Gary Stretch Richards who was apparently head over heels in love, became true partners in crime. Joanna Dennehy slaughtered three men brutally, plunging them to their untimely death. Let’s analyze and dive into the corrupted psyche of this troubled woman and what motivated her to take on the full-blown profession of a serial killer/Spree killer. When the number of women in the serial killing world is scarce.

Who is Joanna Dennehy?

Joanna Dennehy was born in August of 1982 in St Albans, Hertfordshire, Harpenden England. She had what could be claimed as a normal childhood right alongside her sister Maria who could corroborate the story. Kevin Joanna Dennehy’s father worked as a security guard while her mother Kathleen was a shop manager. They both worked to provide a life of comfort to both Joanna Dennehy and her sister Maria. Maria later went on to establish a successful career in the military and then prospered further by being the CEO of her own IT company.

She lived a life of domestic bliss with her sister Maria, who was two years her junior. They shared a bunk bed, stories, and their hopes and dreams as most siblings do. Joanna Dennehy even managed to be a star performer at her school Roundwood Park and went on to represent her school in Hockey and netball. Impressed by her skills and agility her parents enrolled her in tuitions in hopes of their talented daughter, Joanna Dennehy being a lawyer and prospering in life. She lived a life of normalcy, loving fashion, makeup, and her dolls as any girl her age would.

Drastic turn in the Life of Joanna Dennehy

Joanna Dennehy soon entered her teens and things started to go haywire, from this point onwards in her life. Joanna Dennehy fell into the captivating company of the older boys who let her skip classes and engage in nefarious activities of doing drunks and binge drinking alcohol. By the time Joanna Dennehy was sixteen, she started to show up to school under the influence and drug-ridden.

Her grades slipped and her bright future seemed to be sliding further away from her grasp. To make matters worse she engaged in a romantic relationship with a boy five years her senior named John Treanor who eventually left her with a child in her arms.

Joanna Dennehy, like any young girl, didn’t want to spend the rest of her early youth taking care of a child. Thus began her tale of engaging in self-sabotaging behavior of drugs, alcohol, and even self-harming. Her mental health deteriorated and she ran away from the comfort of her parent’s home. Soon she had another child to take care of and frustrated with her life she started cheating on her partner with both men and women leading to their estrangement.

Maybe the start of a new life for Joanna Dennehy

Joanna Dennehy to try and fix her sinking relationship with John and with hopes of a new life moved to East Anglia. But her behavior took a turn for the worse. She started working as a farm laborer without any proper remuneration. Sometimes she was even rewarded with alcohol instead which pushed her deeper into the clutches of alcoholism.

She started to show early signs of abusive behavior and violence. This led to John Treanor abandoning her and taking the children away from the toxic environment she had created for them.

Free to live a life of alcoholism and crime Joanna Dennehy, circulated East Anglia, robbing areas and engaging in prostitution to sponsor her drinking and drugging habits. In February 2012, she was admitted to a hospital, where she was diagnosed with antisocial personality disorder and Obsessive-compulsive disorder. After being released from the hospital in Peterborough city, she continued to live in the city itself continuing with her reckless and self-sabotaging behavior of drinking, drugs, and self-harm. She even acquired a tattoo in the shape of a star under her eye through her efforts.

Why murder?

Joanna Dennehy truly lived a troubled life, right in the clutches of various mental health issues and even prostitution and self-harming tendencies. Though these are not excuses, they seem to be the cause of her immense hatred towards men in general and her violent and murderous tendencies. It’s said that she from time to time claimed to want to murder men and enjoy their deaths.

In Peterborough city, she met a man named Gary Stretch Richards who in all Bonnie and Clyde fashion became her accomplice in her crimes and even aided her in them. It was said that he was completely taken in by her beauty and dangerous attitude and thus was ready to do and be anything for her.

Who were the first Victims of Joanna Dennehy?

Joanna Dennehy in proper analogy cannot be termed as a serial killer, thus she has been named a “spree killer” by investigators as she doesn’t have a cooling period that is usually indicative in serial killer history.

Her first victim was a man of 31 years named Lukasz Slaboszewski whom she met while drinking, soon after drinking together for a few days Joanna Dennehy decided to murder him. She managed to lure him to a home owned by her landlord and then afterward proceeded to brutally stab him right through his heart.

After dumping his body in a dumpster, Joanna Dennehy was on the lookout for the next victim instantly. This time she chose her homeowner and another roommate. The fifty-six-year-old John Chapman, her roommate, was murdered in the same fashion as her first victim.

Then she moved on to her landowner forty-eight years named Kevin Lee. Psychologists claim that she was suffering from another mental condition named “paraphilia sadomasochism” which meant that Joanna Dennehy enjoyed imparting pain and humiliation to others and being in pain herself. So before she carried out the murder of Kevin Lee she manipulated him into donning a black dress. After horrifically murdering these men, Joanna Dennehy ordered her boyfriend Gary Stretch Richards, and another man Leslie Layton to dispose of the bodies. She also attempted to murder two other men walking their dogs by stabbing them brutally, but they were soon hospitalized and survived the attempted murder.


In November of 2013, Joanna Dennehy confessed to being guilty of three murders and two attempted murder charges. The judge Mr. Justice Spencer, sentenced her to life imprisonment because she had in all awareness and planning murdered three men and tried to murder two more. However, it is interesting to note that Joanna Dennehy claimed that she would never murder women, especially women with children as a mother herself. She further claimed that murdering men was fun.

While in prison she proposed to another woman and an inmate named Hayley Palmer in 2018, they even tried to kill themselves in a suicide pact. She also noted down in her diary a murderous escape that would result in the death and loss of fingers of the policemen.

But Joanna Dennehy’s plans were discovered and foiled as she was ordered to solitary confinement in the prison. In May 2019, she was relocated to the Low Newton Prison of Durham County and spends the rest of her punishment there.


The story of Joanna Dennehy was presented in a documentary named, “the Murdered & Me” in the UK and Ireland on 21st February 2021. This murder story is an unconventional and distinct story fueled by a series of mental health issues and poor decisions.

However, one baffling factor that is noted by crime enthusiasts across the world is how Joanna Dennehy became the dominant partner in her relationship with Gary Richards and succeeded in ordering around a man in her life. Dispelling the patriarchal notion even in the serial killing world, a woman follows along with the man as he commits the murders.

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