Nicola Edgington was born on September 9, 1980. She grew up in East Grinstead, England, with her younger brother and younger sister. As a child, she attended Sackville School. Nicola experienced a troubled childhood and reported that her father abused her. This led to her spending some time in care homes.

As she grew older, Nicola worked various jobs. She was a hairdresser, a shop assistant, and a saleswoman. At the age of 17, she faced a tragedy when she miscarried twins after a violent encounter with a boyfriend. By age 19, she was pregnant again, this time by a boyfriend who dealt drugs. She gave birth to a baby boy who was born three months early. Nicola’s mother, Marion, helped her care for the baby for a time. Eventually, they decided to place the child in foster care.

Nicola later married a Jamaican man, who became the father of her younger son. Sadly, both of her sons were taken into care and eventually moved to Jamaica with her former husband.

On 4 November 2005, Nicola Edgington stabbed her 60-year-old mother, Marion, nine times in Forest Row, East Sussex. She was later convicted of manslaughter due to diminished responsibility. This was based on her diagnoses of schizophrenia and emotionally unstable personality traits. In October 2006, she was sentenced at Lewes Crown Court. Edgington was detained indefinitely under the Mental Health Act 1983. After treatment and evaluation, she was conditionally released in September 2009.

In September 2011, Edgington reached out to her brother on Facebook. She expressed that she felt she was not receiving the help she needed and missed their mother. In early October, she repeatedly contacted the police, claiming she was receiving death threats and had issues with individuals in her flat. Despite her claims being treated as serious, the police did not investigate.

On 10 October 2011, Edgington pleaded with police and local mental health services to detain her, fearing she would be dangerous due to a psychotic breakdown. After being taken to a hospital, she was not admitted securely and left the hospital. That morning, she took two buses to Bexleyheath.

While there, Edgington carried out two attacks. First, she tried to kill 22-year-old Kerry Clark, but Clark survived the attack. The knife Edgington used was taken from her by a member of the public. Then, Edgington stole another knife from a butcher's shop. She stabbed 58-year-old Sally Hodkin, who died from her injuries shortly after.

Following the attacks, Edgington was arrested. Psychiatrists indicated that she was experiencing paranoid delusions and hallucinations. They noted her belief in a 100-eyed monster that was guarding God's throne and that she felt she was in a computer simulation. On 7 February 2013, Edgington was found guilty of attempted murder and murder. The judge sentenced her to life imprisonment, with a minimum of 37 years. The judge noted that while she had significant mental health issues, her actions showed a calculated course of conduct.