William "Bill" Priestley has worked in the criminal justice sector since 1980, He began his career as a police officer and continued in law enforcement with police services in England and Northern Ireland for nearly 25 years. He then went onto to serve as an Inspector of Criminal Justice in Northern Ireland for 12 years. Since 2017, he has worked internationally on police reform projects in Myanmar and The Gambia.

His UK police experience was with Kent Constabulary, the Royal Ulster Constabulary (RUC), and then the Police Service of Northern Ireland (PSNI) following the restructuring of policing in Northern Ireland. During his time as an officer, he gained extensive experience in general policing, community policing, community engagement projects, police training, roads policing, and criminal investigations. In both England and Northern Ireland, he led police community engagement among hard-to-reach groups, including the Roma, Irish Travellers, disaffected youth, and migrant workers. He also served as a first line supervisor in both police services, leading partnership engagement efforts between police and community groups.

During his time as an officer, He was also Head of Race and Diversity for National Police Training (now UK College of Policing) and was the National Programme Manager of the UK Police Programme in response to the Stephen Lawrence Report to address institutional racism. He also managed the UK National Quality Approval Award for Police Training. This included coaching, mentoring, and assessing agencies applying for the award..

As an Inspector of Criminal Justice in Northern Ireland, Bill led Inspection teams examining all major justice organizations including the Police, Public Prosecution Service, Courts, Probation Service, Prisons and Youth Justice. He conducted inspections into Hate Crime, Complaints Handling, Coronial Processes, Youth Conferencing, Legal Aid, Jury Management and Policing with the Community. Bill was the lead Inspector for all inspections of The Office of the Police Ombudsman in Northern Ireland. All Inspection reports were laid before the UK Parliament or Northern Ireland Legislative Assembly. Bill presented findings and recommendations to the Northern Ireland Justice Committee, providing policy advice on criminal justice issues. During his time as an Inspector of Criminal Justice Bill was also a short-term expert for the Council of Europe on police and prison oversight, working in Russia, North Macedonia, Georgia, Ukraine and Serbia.

Bill was the Key Expert for Community Policing in the European Union (EU) funded MYPOL project. He led the Community Policing in Myanmar aspect of the project in accordance with Human Rights and International standards. This included work with the Myanmar Police Force, INGO and NGO stakeholders, other Civil Society Organizations, the EU Delegation, and external project partners. The project unfortunately ended in the wake of the 2021 military coup in Myanmar. Since then, Bill has worked in The Gambia providing assistance and advice to the Gambia Police Force to develop and implement its Police Doctrine to improve service delivery. Additionally, he continues to work from time to time with The Council of Europe, most recently reviewing Georgia’s manual on effective investigative interviewing.

He has authored a number academic articles related to policing, including ‘Recent Judicial Decisions’ for the UK Police Journal and ‘Police Oversight Mechanisms in the Council of Europe Member States.’

Bill holds a Master of Public Administration (MPA), a Master of Laws (LLM), a Batchelor of Science (BSc., hons) and a Certificate of Adult Education (Cert Ed.). In 2018, he was named in Her Majesty The Queen’s New Year’s Honours List as an Officer of the Most Excellent Order of the British Empire (OBE) for services to Criminal Justice.