Custody sergeant vs investigating officer

Custody sergeant versus Investigating officer

The custody sergeant and the investigating officer have distinct and deliberately separated roles in the custody process. This separation is a key safeguard in PACE.

Side by side

	Custody sergeant	Investigating officer
Primary function	To safeguard the welfare and rights of the detained person and to act as an independent check on the investigation team's decisions	To investigate the offence: gather evidence, conduct interviews, and present the case for charging decisions
Independence	Must not be involved in the investigation of the offence for which the person is detained	Directly involved in the investigation; reports to the officer in charge of the case
Decision to charge	The custody officer formally charges the person after a charging decision has been made by the CPS or, for minor offences, by the custody officer themselves	Presents the evidence to the CPS and recommends a charging decision, but does not make the charging decision
Detention authorisation	Authorises detention, reviews the grounds for continued detention, and must release the person if grounds are no longer met	Has no power to authorise or extend detention; must justify continued detention to the custody officer
Custody record	Responsible for opening, maintaining, and ensuring the accuracy of the custody record	May make entries on the custody record relating to the investigation but is not responsible for its overall maintenance
Welfare checks	Responsible for arranging regular welfare checks and for the physical and mental health of the detainee	Has no specific welfare responsibilities during custody, though must flag concerns to the custody officer

Which applies

The separation of the custody officer role from the investigation is one of the fundamental principles of PACE. It ensures that the decision to continue detaining someone is made independently of those with an interest in the outcome of the investigation. In practice, both roles are under pressure of time and must communicate effectively to ensure that the investigation proceeds efficiently and the detainee's rights are protected.

Last updated 24 September 2026