Operation prudent – supporting response officers with investigations

Operation prudent aims to:

• improve the quality and efficiency of investigations conducted by response officers
• create good working relationships between detective sergeants and response teams
• ensure cases receive the right outcomes in a timely manner

The intended outcomes of Operation prudent are to:

• increase the number of positive outcomes for investigations
• improving officer decision-making so cases can be resolved quicker
• reduce triage refusals by the Crown Prosecution Service (CPS) by improving the quality of cases
• improve satisfaction and outcomes for victims

Northamptonshire Police faced a reduction in positive outcome rates, an increase in time taken for cases to be completed, and high levels of cases being rejected by the CPS. As a result, the force received a ‘requires improvement’ score in a His Majesty’s Inspectorate of Constabulary and Fire & Rescue Services (HMICFRS) PEEL inspection.

This led to the force setting up Project Sherlock in June 2023 with the aim of improving the investigations carried out by the force. This was driven by a chief superintendent, leading a small team of police officers and staff comprising of an inspector, a detective sergeant, an analyst and a project manager. The team brainstormed means by which investigations could be improved, and one of the initiatives they came up with was Operation Prudent.

Northamptonshire Police operate an omni-competent model, whereby response officers do not just have responsibility of responding to 999 calls, but they also deal with volume crime (or PIP1) investigations. Much like most forces, Northamptonshire Police response teams are the youngest in service and most inexperienced staff in the Force. This means that they have less experience in decision making around investigative cases. This can lead officers to spend too much time investigating unsolvable cases, as they are not confident in their decision making to file a case. Conversely, response officers may not realise when a case is worth investigating further, leading to solvable cases being filed and reduced positive outcomes.

The goal of Operation prudent is to improve the investigations carried out by response officers by providing them with support from the following subject matter experts:

• detective sergeants (DSs), who are specialists in investigating cases and know what reasonable lines of inquiry are for each case, and when they should be filed
• evidential review officers (ERO), who are police staff tasked with reviewing cases created by investigating officers and deciding whether the case is strong enough to progress
• case builders, who are police staff tasked with taking the cases that officers investigate and building them on the computer system so they can be sent to the CPS for review. This is a time-consuming job, so the role of case builders was created to improve efficiency and allow police officers to focus on competing demands

Operation prudent surgeries take place every Wednesday in the North and West local policing areas (LPAs) from 12pm-4pm. All DSs involved in Operation prudent were sent an email at the beginning of the operation with the dates of their scheduled surgeries, and a guidance form detailing the background, purpose, method, performance framework and other details of Operation prudent. 

DSs attend these surgeries on a rotating schedule and are assigned to run two surgeries a year. The assigned DS contacts the response inspector prior to attending their surgery to receive a list of specific investigations and officers attending (those with a high number of crimes or complex investigations). Each surgery is also attended by an assigned ERO and case builder who can support on other aspects of the investigation.

At the end of the surgery, the DS fills in a returns form which lists the cases they reviewed and what action they took to support the investigation. This is sent to the Project Sherlock DS, who completes a spreadsheet collating the returns, allowing for tracking of how many cases have received support.  

These figures are then fed back to the Project Sherlock gold and silver meetings to update on the operation’s progress. The gold meeting, chaired by the assistant chief constable, is held quarterly and offers a strategic overview of Project Sherlock. The silver meeting, chaired by the chief superintendent, is held monthly and has a more tactical approach where the details of initiatives are discussed.

In 2025, Operation prudent resulted in almost 250 cases being reviewed by DSs. An average of 8.1 cases were reviewed per week, with an average of 1.4 filed and 0.6 having a police decision made (PDM) per week.

Having DSs working directly with response teams has built relationships between individual officers and has also improved relationships between the criminal investigation department (CID) and response teams. This has encouraged better understanding of workloads between the teams and encouraged improved cooperation. The Project Sherlock team has received positive feedback regarding Operation prudent from response teams and DSs.

Operation prudent has also become a recognised practice by HMICFRS following a recent force inspection and has been included as a case study of effective investigative practice. 

There was some initial resistance to Operation prudent from some DSs who felt they did not have time to run the surgeries. However, given the time per surgery is only four hours and DSs are only expected to attend two surgeries a year, time should not be an issue for implementation. Additionally, over time views towards the operation have improved, and it has become business as usual across the investigative teams.

The Project Sherlock team have been vital in running Operation prudent. The DS within the team has overseen coordination, including chasing DSs for returns. The chief superintendent has provided strategic oversight and helped drive the operation by getting force-wide support at a senior level. This support is crucial for the success of the operation. The email sent out to all DSs participating in the operation was co-signed by all four chief superintendents, helping stress the importance of the operation and the necessity of delivering the surgeries.