Key Points
- Fatal Incident in Croydon Custody: Jason Mattison, 52, died after being found unresponsive in his cell at the Windmill Road Custody Suite in Croydon.
- Timeline of Arrest: Mr Mattison was taken into custody on 19 August following his arrest on a no-bail warrant issued by Croydon Magistrates’ Court for failing to appear on charges of being drunk and disorderly.
- Discovery and Emergency Response: Officers and custody personnel found Mr Mattison unresponsive on his cell floor at approximately 1:30 am on 21 August. Medical first aid was administered immediately by staff and paramedics, but he was declared dead at the scene.
- Welfare Check Protocols: Under police guidelines, Mr Mattison was required to be monitored via half-hourly welfare checks.
- IOPC Notice Served: The Independent Office for Police Conduct (IOPC) has launched an investigation and served a formal notice of investigation on a designated detention officer regarding allegations of a missed welfare check and inaccurate recording of records.
- Post-Mortem Examination: An initial post-mortem has been conducted, with additional toxicology and specialist tests pending to establish the exact cause of death.
Croydon (South London News) November 11, 2026 – A 52-year-old man, Jason Mattison, has died while being held in police custody in South London, initiating an extensive independent inquiry into the actions of custody staff and adherence to inmate welfare protocols. The incident occurred at the Windmill Road Custody Suite in Croydon during the early hours of 21 August, where Mr Mattison had been detained for two days following an arrest on outstanding court warrants.
Mr Mattison was originally taken into custody by Metropolitan Police officers on 19 August. His arrest was executed pursuant to a no-bail warrant issued directly by Croydon Magistrates’ Court after he failed to appear in court to answer charges relating to being drunk and disorderly. Pending a formal court appearance, he was remanded at the Windmill Road facility under standard detention procedures.
At approximately 1:30 am on 21 August, custody personnel found Mr Mattison lying unresponsive on the floor of his designated cell. On-site custody officers alongside arriving London Ambulance Service paramedics immediately commenced emergency first aid resuscitation procedures. Despite their medical efforts, Mr Mattison could not be revived and was pronounced dead at the scene shortly thereafter.
How Is the Independent Office for Police Conduct Investigating the Death?
Following the declaration of death inside the custody facility, the Metropolitan Police Service made a mandatory referral to the Independent Office for Police Conduct (IOPC), the statutory oversight body responsible for examining serious incidents and deaths involving police contact in England and Wales.
The IOPC immediately deployed investigators to the Windmill Road Custody Suite to secure the custody area, collect physical evidence, and begin securing digital and documentary evidence, including closed-circuit television (CCTV) footage and custody logbooks.
The oversight body confirmed that Mr Mattison was assessed upon intake and placed under a regime requiring mandatory half-hourly welfare checks by custody staff. These routine checks are designed to ensure the continuous safety and health monitoring of individuals detained inside police cells.
As part of their ongoing inquiries, IOPC investigators have formally served a notice of investigation on a designated detention officer working at the suite. The notice relates to serious allegations that the officer failed to perform a scheduled welfare check on Mr Mattison prior to his discovery, and subsequently recorded inaccurate information into the official custody management system indicating that the check had been completed.
The serving of an IOPC notice informs the individual that their conduct is under investigation; it does not in itself carry a presumption of guilt or automatically signal that criminal or disciplinary proceedings will follow.
What Are the Next Steps in Establishing the Cause of Death?
Pathologists have conducted an initial post-mortem examination on Mr Mattison to determine the physical cause of death. However, preliminary physical examinations did not yield a conclusive result, necessitating further forensic analysis.
The IOPC indicated that comprehensive secondary testing, including toxicology reports and detailed histological examinations, has been ordered. The results of these tests typically require several weeks to complete, after which a finalized post-mortem report will be submitted to the HM Coroner to assist with the formal inquest proceedings.
Investigators are continuing to review all cell check logs, electronic door entry telemetry, and CCTV footage from inside the custody suite. They are also interviewing staff members, paramedics, and medical professionals who attended the scene during the emergency response.
Background of Custody Safeguards and IOPC Oversight
Police custody suites in England and Wales operate under strict legislative frameworks governed primarily by the Police and Criminal Evidence Act 1984 (PACE) Code C. Code C outlines the fundamental detention, treatment, and questioning standards required for all individuals detained by police officers.
Under these statutory guidelines, custody officers and designated detention staff maintain a legal duty of care toward detainees. Intake assessments categorize detainees based on risk factors, such as alcohol or drug dependence, medical conditions, and mental health vulnerability. Detainees assessed under standard monitoring protocols are subject to routine checks at intervals not exceeding 30 minutes, during which staff must visually inspect the individual and ensure they are responsive.
When a death occurs in police custody, independent oversight by the IOPC is legally mandatory. The IOPC operates independently of the police, government, and interest groups, carrying out impartial investigations to establish the facts, assess whether police actions met professional standards, and determine whether any criminal offenses or disciplinary misconduct occurred.
Prediction: How This Development Can Affect Detainees, Police Personnel, and Public Trust
This ongoing investigation and its eventual findings are likely to exert significant impacts across several key areas of police operations, staff accountability, and community relations within the London area:
Impact on Custody Staff and Operational Procedures
The serving of a formal misconduct notice on a designated detention officer highlights heightened scrutiny surrounding administrative logging and physical checks within police facilities. If the IOPC finds evidence of systemic failures or procedural falsification, the Metropolitan Police Service may face demands to implement automated or biometric check-verification systems within custody suites to eliminate reliance on manual logging. Custody personnel across the force will likely experience increased operational oversight and refreshed training regarding Code C compliance.
Impact on Detainees and Their Families
For individuals taken into police custody and their families, the inquiry reinforces ongoing concerns regarding safety, health monitoring, and duty of care within police cells—particularly for detainees arrested under circumstances involving substance use or minor public order offenses. Clear findings from the IOPC inquiry could lead to stricter pre-detention medical screening requirements for individuals suffering from acute intoxication or vulnerability.
Impact on Public Confidence and Legal Accountability
Incidents involving deaths in custody routinely affect public trust in law enforcement accountability. The transparency and thoroughness of the IOPC’s final report will play a crucial role in maintaining public confidence in independent oversight mechanisms. Should the investigation conclude that negligence or record falsification contributed to the outcome, it may lead to formal disciplinary proceedings, referral to the Crown Prosecution Service, and recommendations for structural reform across Metropolitan Police custody operations.
