Understanding the role and value of investigative strategies and plans in serious and complex investigations within non-specialist policing contexts

This research examined the role and value of investigative strategies and plans in serious and complex investigations within non-specialist policing contexts. The issue was chosen because investigative quality, public confidence, supervision and investigator experience are under increasing scrutiny. Recent inspection findings identify effective supervision, high-quality investigation plans, reasonable lines of enquiry and an investigative mindset as key features of effective investigations. However, there remains limited understanding of how investigators and supervisors apply these processes in day-to-day operational policing.

The study used a qualitative methodology. Semi-structured interviews were conducted with investigators and supervisors working across Professionalising Investigation Programme (PIP) level one and two environments. This approach was chosen because the research sought to understand practitioners’ experiences rather than to measure performance outcomes. Interview data was analysed using Braun and Clarke’s six-stage thematic analysis, allowing common patterns and differences to be identified.

The findings showed that participants did not reject investigative strategies and plans. Instead, they questioned how plans are sometimes written, reviewed and applied. Strategies were generally understood to provide direction, while plans were seen as the practical actions required to progress an investigation. Plans were valued when they were specific, proportionate, current and relevant. They were less useful when generic, copied or used mainly to satisfy organisational requirements.

The main conclusion is that policing does not need more plans, longer plans or more frequent reviews for their own sake. It needs higher-quality plans that serve as living blueprints for effective investigations: structured, proportionate and adaptable guides that support investigative thinking, reasonable lines of enquiry, supervisory oversight and professional judgement.

The research recommends a quality-focused standard for investigation plans, brief supervisory discussions at key stages of the investigation and proportionate dip-sampling and feedback to assess plan quality without creating unnecessary bureaucracy.

This study examined how investigators and supervisors apply investigative strategies and plans in real-world operational settings. Practical application is shaped by experience, organisational culture and the pressures of day-to-day policing. For this reason, the study adopted an interpretivist approach. This was particularly appropriate because investigative decision-making is not purely procedural or objective. This mattered because investigators do not make decisions in a vacuum. Their decisions are shaped by law, policy, supervision, workload, experience and the culture of the team around them. A purely quantitative approach would not have captured these subtleties or the realities of investigative work. A qualitative methodology was selected as the most appropriate approach.

This study adopted a qualitative design that incorporated both exploratory and explanatory elements. Semi-structured interviews provided a framework while still allowing participants to speak openly. This method aligned with the study’s aims for several reasons. Investigative work involves discretion, competing priorities and organisational pressures that are best understood through open discussion. Participants had varying levels of experience, and semi-structured interviews allowed questioning to flow accordingly. Investigators were able to describe practices that differed from organisational expectations, and interviews helped elicit these realities.

A purposive sampling strategy was used to select participants with directly relevant experience in the applied setting. Participants included both PIP1 and PIP2-accredited investigators and supervisors. The final sample comprised investigators and supervisors working across PIP1 and PIP2 investigative environments. Participants were recruited through professional policing networks and organisational contacts. Data was collected through semi-structured interviews guided by an interview plan developed from the literature review and research objectives. The plan included open-ended questions exploring participants’ experiences of investigative strategies and plans, perceptions of their usefulness, supervisory oversight, organisational considerations, pressures and their investigative confidence and professional development. The data was analysed using thematic analysis.

This project was completed in July 2026.

View report in National Police Library