Karl Quincey, the convicted murderer jailed for one of Devizes' most shocking killings, died after numerous attempts at self-harm while in prison.
The 48-year-old developed sepsis following a serious act of self-harm at HMP Wakefield which involved inserting the arm of a pair of glasses into his open chest wound, according to an independent investigation by the Prisons and Probation Ombudsman.
Quincey was serving a life sentence with a minimum term of 17 years for the murder of Barry Cooper, who was stabbed to death in Devizes in 2008.
His conviction in 2010 brought to an end a case that horrified the town and left a lasting impact on the victim's family and the wider Wiltshire community.
At his trial, the court heard how Mr Cooper was fatally attacked in his home in an act described by the judge as brutal and senseless.
Quincey, who was 35 at the time of sentencing, was told he would serve life in prison, with release dependent on the Parole Board being satisfied that he no longer posed a danger to the public.
Reporting at the time described the killing as one of the most serious crimes Devizes had seen in recent years, shattering the sense of safety in the normally quiet market town.
Years later, Quincey remained behind bars after the Parole Board ruled that he should continue to serve his sentence.
In 2011, he was told he must stay in prison because of ongoing concerns about the risk he posed and his lack of progress in custody.
Judges and parole officials said he had not demonstrated sufficient stability or insight to justify any move towards release, reinforcing the view that he remained a danger.
Behind prison walls, Quincey's life was marked by severe mental health difficulties and repeated acts of extreme self-harm.
According to the Ombudsman's report, he had diagnoses of emotionally unstable and dissocial personality disorders and a long history of harming himself, including cutting and repeatedly reopening a chronic wound to his chest.
On many occasions, he inserted foreign objects into the wound, causing repeated infections and serious damage to his health.
Between 2008 and 2022, prison staff placed Quincey under suicide and self-harm prevention procedures on at least 25 occasions.
His behaviour became increasingly difficult to manage, and in September 2022 he was transferred from prison to Broadmoor Hospital, a high-security psychiatric hospital, under the Mental Health Act.
Clinicians believed his escalating self-harm put him at high risk of serious injury or death.
Despite months of intensive support, Quincey failed to engage meaningfully with treatment at Broadmoor and continued to seriously injure himself.
Hospital staff concluded they could no longer safely manage him in that setting, and in July 2023 he was transferred back to the prison estate, arriving at HMP Wakefield.
Barry Cooper was murdered by Quincey
From the moment he arrived at Wakefield, dubbed 'Monster Mansion' due to its high number of serious offenders, Quincey was recognised as being at high risk of suicide and self-harm.
He was placed in the prison's healthcare inpatient unit and monitored under constant supervision.
Staff sat outside his cell at all times and carried out regular reviews involving prison officers, managers and mental health professionals.
The Ombudsman's investigation found that prison and healthcare staff took many positive steps to support Quincey and manage his risks.
Reviews were held regularly, and staff who knew him well were often assigned to supervise him.
However, the report into his death on October 21, 2023 also highlighted shortcomings in senior oversight, particularly in the final weeks of his life.
In October 2023, Quincey was moved to a different cell within the healthcare unit due to operational needs.
Around the same time, he was told that his incentives level could be reduced if he failed to engage with education or work.
This would have meant losing access to items such as his games console and music, which staff recognised as important protective factors for him.
The Ombudsman found that both the cell move and the threat of losing incentives were known triggers for Quincey and should have prompted greater senior, multi-disciplinary input.
Shortly afterwards, Quincey reopened his chest wound and told staff he was "waiting for the right moment".
Despite this escalation, no urgent case review took place.
On October 15, 2023, while still under constant supervision, Quincey inserted the arm of a pair of glasses into his open chest wound.
He then calmly handed a note to an officer instructing her to call for an emergency response.
Staff immediately summoned medical help and paramedics transferred him to Leeds General Infirmary under guard.
While in hospital, Quincey repeatedly refused surgery to remove the object from his chest and expressed a wish to die.
Doctors assessed that he lacked the mental capacity to make decisions about his treatment and plans were made to intervene under the Mental Health Act.
However, before this could happen, his condition deteriorated further.
Over several days, the infection spread and Quincey became increasingly weak and unresponsive.
On October 21, hospital staff told prison officers that he was nearing the end of his life.
Despite this, he remained restrained until shortly before his death.
A post-mortem examination later confirmed that he died from sepsis caused by infection of a foreign body in the heart.
The Ombudsman's report criticised aspects of the use of restraints during Quincey's final hours, stating that he should not have died while restrained and that his medical condition meant he posed little or no risk at that stage.
The report made a series of recommendations aimed at improving the management of high-risk prisoners and ensuring that senior staff are more closely involved in critical decisions.
An inquest into Quincey's death concluded in November 2025 and recorded a verdict of suicide.