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Investigation career pathway

Career stories, available roles, progression and working environment.

Detective Constable David Thomason – investigation

The investigation job family covers both warranted officers (also referred to as detectives) and police staff investigators. While investigations are conducted by investigators in a variety of different roles depending on the seriousness of the offending, David in this career story conducts serious and complex criminal investigations (PIP 2).

The Code of Practice to the Criminal Procedure and Investigations Act 1996 (CPIA) defines a criminal investigator as:

An investigation conducted by police officers with a view to it being ascertained whether a person should be charged with an offence, or whether a person charged with an offence is guilty of it

While there is no definition of a serious and complex crime, factors that may identify an offence as such include those that: 

  • involve the use of violence, including the use of weapons and firearms
  • are sexual assaults
  • involve physiological trauma or impact
  • result in substantial financial gain
  • cause substantial financial loss to the victim
  • are conducted by a large number of persons in pursuit of a common purpose 
  • cause death and serious injury on the roads

All police officers and some police staff are investigators and have a responsibility to investigate crimes according to the level of learning and development they have received. 

The professionalising investigation programme (PIP) defines four levels of investigator according to the seriousness of the criminality and provides an integrated learning and development programme for each role within the four levels. 

Career stories

Possible entry routes

  • police constable 
  • police staff


Investigators conducting serious and complex (PIP 2) investigations will impartially follow all reasonable lines of enquiry to gather material that will point either towards or away from a suspect. 

This process may result in the suspect being prosecuted in the courts, out-of-court disposal, community resolution or no further action being taken. 

In many cases, despite best efforts, an investigation will not find enough material to make a charging decision. 

This may be because the offender has left very little evidence or because there are no viable lines of enquiry to pursue. 

In these cases, it is still important to record the outcome of the investigation accurately for intelligence purposes. This will help the police service to identify crime patterns and take proactive action to reduce risk and prevent further crimes. 

Using an investigative mindset, investigators will plan, understand, examine, record and evaluate the material they gather, including victim and witness accounts. They will use technical and scientific experts to maximise evidential opportunities.

An effective investigation and case management processes will support the criminal justice system to achieve successful outcomes. 

Throughout the investigation and criminal justice process, victims, witnesses and suspects should be supported according to their diverse needs, allowing them to give their best evidence. 

Any risks should be assessed and effectively managed and they should be directed to appropriate support services. 

Core investigative topics

  • victim and witness care and support
  • suspect management 
  • investigative mindset 
  • safeguarding
  • legal and judicial processes
  • interviewing
  • leadership
  • managing investigations
  • digital/cybercrime
  • problem-solving
  • decision-making 


The majority of serious and complex investigators will work in a crime investigation department investigating a broad range of criminal offences. However, there are a number of specialisms in this role that investigators could follow. These include:

Investigators could also specialise in digital media or cyber investigation, fraud or financial investigation. 

Specialist roles


As a serious and complex investigator at PIP 2, you will have already developed your career from that of a police constable or police staff investigator at PIP 1. 

You now have the opportunity to develop your career further within the investigation world, with many investigators progressing to supervisory or management roles, aspiring to be a senior investigating officer (SIO) or strategic investigator. 

Many serious and complex investigators, however, go on to develop their specialist knowledge at PIP 2, eg, as a child abuse investigator or as a digital media investigator. 

Many police officer investigators may consider future promotion opportunities and roles within the uniform aspects of policing, such as response, roads or neighbourhood. 

It is likely that a constable or a member of police staff will have some experience from other job families, as well as being an investigator at PIP 1. However, it is also possible that you come straight into the role as a serious and complex investigator through a direct-entry detective. 

A member of police staff may also be directly employed into a PIP 2 investigator role.

If, as a police constable PIP 2 investigator, you are looking to progress further through the police ranks, you should read the national police promotion framework (NPPF) information. 

It may not always be possible to progress through the ranks within a particular job family, as forces may assign newly promoted individuals or those in acting posts, in line with organisational need. 

Police staff should also consider career progression and look for promotion development opportunities with their chosen job family.

    Progression routes

    Fast track

    The fast track programme for serving constables is a development programme and promotion mechanism to enable the most talented serving police constables to advance to the rank of inspector within two years.

    Professionalising investigation programme (PIP)

    The PIP programme provides an incremental development pathway that provides a consistent programme of registration, examination, training, workplace assessment and certification to a national standard at each level. Achievement of PIP is supported by continuous professional development.

    The NIE (national investigators exam) is a gateway exam to PIP 2 learning.

    Level Roles Specialisms
    PIP 1 - volume and priority crime  
    PIP 2 - serious and complex crime
    PIP 3 - senior investigative officer
    • counter-terrorism SIO
    • kidnap and extortion SIO
    PIP 4  
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