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How to Become a Detective: DHEP, the PC Route, the NIE and PIP2

To become a detective in England and Wales you join a police force and gain PIP2 accreditation as an investigator. You can join directly as a trainee detective on the two-year detective degree holder entry programme (DHEP), or serve as a uniformed constable and then move into CID. Both routes need a pass in the National Investigators' Exam (NIE).

Updated 2026-10-30 · 8 min read · Checked against official sources

How to become a detective comes down to one destination and two main roads. The destination is accreditation at PIP2, the level of the Professionalising Investigations Programme for serious and complex investigations. The roads are the detective degree holder entry programme (DHEP), which recruits trainee detectives directly, and the internal route, where you serve as a uniformed constable first and then move into CID. Both run through the National Investigators' Exam (NIE). This guide compares the routes, explains each step, gives realistic timescales and pay figures, and shows how to prepare for the exam.

If you are already in an investigative post and the NIE is on your horizon, take the free NIE diagnostic to see where you stand.

How to become a detective: the three routes

DHEP (direct detective entry) Internal route (PC to TDC) Police staff investigator
Who it suits Graduates who want to investigate from day one Serving or new constables who want uniform experience first People who want investigative work without a warrant
Entry requirement A degree in any subject (some forces exclude the professional policing degree) Completed probation as a constable Force job requirements
Length About 2 years to the end of probation Probation, then about a year or more as a TDC Varies
NIE Yes, during the programme Yes, as a TDC Yes, for PIP2
End point Detective constable Detective constable PIP2 accredited investigator (not a warranted detective)

Not every force recruits through every route every year. Check your force's recruitment pages for current intakes.

How to become a police detective through the DHEP

The detective degree holder entry programme is a two-year route for people who already hold a degree. You join as a police officer with a full warrant, but your training and early postings are designed around investigation.

Avon and Somerset Police's DHEP page gives a typical picture, checked on 30 October 2026:

  • Length: two years, with probation running for the whole programme.
  • Qualification: a Level 6 Diploma in Professional Policing Practice, delivered with a university partner and funded by the force.
  • Eligibility: an undergraduate degree in any subject at the time you apply (predicted results are not accepted). You are not eligible if you hold, or are working towards, a degree in professional policing.
  • Structure: a first block of about 14 weeks covering law, personal safety, driving and systems, then time with response teams, then investigative postings.
  • NIE: taken in the second year in that force. Other forces set different points.

The programme is demanding because you learn policing and investigation at the same time. You also spend time in uniform; the DHEP does not skip frontline policing altogether.

Key fact: The DHEP is designed by each force with a university partner, so the timing of the NIE, the postings and the academic work differ between forces. Read your force's own programme description before you apply.

The internal route: from constable to trainee detective

Most serving detectives came this way.

  1. Join as a constable through an entry route your force offers, such as the police constable degree apprenticeship or the degree holder entry programme for constables.
  2. Complete your probation. Use it to build investigative experience: file building, interviews, statements and case handling to the PIP1 standard.
  3. Apply for a trainee detective constable (TDC) post when your force advertises them. Selection usually involves an application, an interview or assessment, and a check of your record.
  4. Pass the NIE. Your force's NIE liaison contact registers you for a sitting.
  5. Complete PIP2. This means your force's investigator development course (many forces still call it the ICIDP, the Initial Crime Investigators' Development Programme) and a portfolio of evidence from real investigations.
  6. Get signed off as a PIP2 accredited investigator. You are then a detective constable.

Arrangements vary between forces: some advertise TDC posts only to officers who have finished probation, and the point at which you sit the NIE depends on local policy. Ask your force's crime training team what applies to you.

Exam tip: Your probation is the best preparation for the NIE. Every arrest, interview and file you deal with uses the Part 1 procedure the exam tests. Learn the rule behind each step as you go, and revision later is much lighter.

Police staff investigators

Many forces employ police staff (civilian) investigators in areas such as fraud, safeguarding, volume crime and case review. The College of Policing's NIE handbook opens the exam to police staff investigators selected for PIP2. Accredited staff investigators do investigative work to the same standard, but they don't hold a warrant, so they don't have a constable's powers and aren't called detectives. The College's investigation career pathway shows the roles at each PIP level.

The NIE and PIP2: the step every detective takes

PIP is the national framework for investigative standards. HMICFRS describes four levels:

Level Covers Typical roles
PIP1 Priority and volume crime Uniformed constables, staff investigators, investigative supervisors
PIP2 Serious and complex investigations Detective constables and sergeants, specialist investigators
PIP3 Major investigations Senior investigating officers
PIP4 Strategic oversight of complex and high-profile investigations Strategic investigators and advisers

The NIE is the gateway to PIP2. According to the College's NIE candidate handbook for 2026, it is:

  • 80 multiple-choice questions in two hours, taken online;
  • marked out of 70, after the 10 weakest-performing questions are removed;
  • passed at 55.7% (39 of 70) in 2026, with 85.7% or more an exceptional grade;
  • run four times a year;
  • based on parts 1 to 4 of Blackstone's Police Investigators' Manual for the exam year.

A pass is valid for three years less one day, and most investigators complete PIP2 within six to 12 months of passing. Our National Investigators' Exam guide has the full format, registration process and rules, and NIE exam questions shows how the questions work.

How long does it take to become a detective?

Stage DHEP Internal route
Initial training and probation About 2 years, with investigation built in 2 to 3 years as a uniformed constable
Waiting for a TDC post Not applicable Depends on vacancies: months to years
NIE revision About 14 weeks (College recommendation) About 14 weeks
PIP2 after passing Built into the programme Usually 6 to 12 months
Realistic total from joining About 2 years About 3 to 5 years

Timescales depend heavily on your force's vacancies and how quickly it can release you for training. A failed NIE adds at least a quarter, because the next chance is the following sitting.

Detective constable salary

Detective constables are paid on the national constable scale; the "detective" prefix doesn't change pay (see our police ranks guide). From 1 September 2025 the scale ran from £31,164 at pay point 1 to £50,256 at pay point 7, according to the Police Remuneration Review Body's 2026 report. The government awarded 3.5% from 1 September 2026; Avon and Somerset now advertises DHEP starting pay of £32,256 at pay point 1.

You move up one point a year if you meet the pay progression standard. Some forces start new officers at pay point 2. On top of basic pay, detectives often earn overtime, and officers in London and the South East receive regional allowances. Promotion to detective sergeant brings the sergeant scale: see police sergeant pay.

Skills forces look for in a trainee detective

  • Investigative mindset: keeping an open mind, testing every account and following the evidence rather than a theory.
  • Interviewing: planning and conducting interviews with victims, witnesses and suspects.
  • Written work: clear statements, case files and disclosure schedules. Detectives write a great deal.
  • Organisation: managing a caseload of live investigations with competing deadlines.
  • Resilience: much detective work involves serious harm, including sexual offences and child abuse.
  • Legal knowledge: the law and procedure in the Investigators' Manual, which is what the NIE tests.

Exam tip: Interview panels for TDC posts often ask about a case you handled. Pick one where you can explain the legal decisions (grounds for arrest, the caution, disclosure) as well as the outcome.

What a detective constable does day to day

The work depends on the unit, but most DCs spend their time on a mix of:

  • taking over cases from response officers and reviewing what evidence exists;
  • planning and conducting interviews, including suspect interviews under caution with a legal adviser present;
  • gathering evidence: CCTV, phone and financial records, forensic submissions and house-to-house enquiries;
  • applying for warrants and production orders, and executing them;
  • building case files for the Crown Prosecution Service and seeking charging decisions;
  • meeting disclosure duties under the Criminal Procedure and Investigations Act 1996;
  • keeping victims informed and supporting witnesses through to trial;
  • giving evidence in court.

Expect paperwork, deadlines set by custody time limits and court dates, and on-call duties in some units. Much of the job is careful, unglamorous work that makes or breaks a prosecution.

Preparing for the NIE as a trainee detective

Most candidates revise around a live caseload, so the plan has to be realistic.

  1. Start 14 weeks out. The College recommends at least 14 weeks of independent study. Book the time with your supervisor; many forces give some study time, but you will need your own too.
  2. Use the edition for your year. Questions come only from the Investigators' Manual named in the handbook for your sitting.
  3. Part 1 first. Procedure (detention, interviews, identification, disclosure) underpins the rest and matches what you do at work.
  4. Questions every day. Twenty minutes of topic questions beats an hour of re-reading. Review every wrong answer against the manual.
  5. Three full mocks. Sit 80 questions in two hours at least three times before the real thing, and aim for about 66%, 10 points above the pass line.

Key fact: The College says the NIE isn't a test of pure recall. Questions give you a scenario and ask you to apply the law, so practise applying it, not just reading it.

After accreditation

Once accredited, detectives can move into specialist units such as major crime, public protection, fraud, cybercrime or serious and organised crime. Some go on to PIP3 as senior investigating officers. Promotion follows the same path as uniform: a detective constable who wants to become a detective sergeant sits the sergeants' exam like any other constable.

Test yourself

  1. Take the free NIE diagnostic: 20 questions in 30 minutes.
  2. Work on Part 1 procedure first with the detention and custody quiz and the interviews quiz.
  3. When you have covered all four parts, sit the free 80-question NIE mock 1 under timed conditions.
  4. For more full mocks and every explanation, see Pro.

The sample questions below come from our NIE bank. This is an independent revision site, not affiliated with the College of Policing or any force. Recruitment rules change, so always check your force's own pages.

10 free NIE practice questions with answers

Try each one, then open the answer. For a timed experience use the free mock exam.

  1. 1. THORNE's interview is interrupted for a 45-minute meal break. When the interview resumes, which of the following is correct?

    1. A. The caution must always be repeated in full after any break in the interview, however short it was.
    2. B. No reminder of the caution is needed, because the break lasted for less than one hour.
    3. C. THORNE must be made aware he remains under caution and, if in any doubt, cautioned again in full.
    4. D. A fresh caution is needed only if a different officer resumes the interview after the break.
    Show answer

    C. THORNE must be made aware he remains under caution and, if in any doubt, cautioned again in full.

    Under Code C para 10.8, after any break in questioning under caution the person must be made aware that they remain under caution, and if there is any doubt the relevant caution should be given again in full when the interview resumes. Code E para 3.16 adds that the suspect should also be reminded of the right to legal advice if not exercised.

    Source: PACE Code C (2023), para 10.8; PACE Code E (2018), para 3.16

  2. 2. FORBES, a serving prisoner, has a psychoactive substance (not a controlled drug) in his cell. He knows what it is and intends to take it himself. Which is correct?

    1. A. FORBES commits an offence only if the substance is proved to be harmful to his health.
    2. B. FORBES commits the s.9 offence of possessing a psychoactive substance in a custodial institution.
    3. C. FORBES commits no offence, as the substance is for his own consumption and he has no intent to supply.
    4. D. FORBES commits possession with intent to supply under s.7, as a prison is treated as a place of supply.
    Show answer

    B. FORBES commits the s.9 offence of possessing a psychoactive substance in a custodial institution.

    Section 9 makes it an offence to possess a psychoactive substance in a custodial institution, knowing or suspecting it is one, with intent to consume it for its psychoactive effects. 'Custodial institution' (defined in s.6) includes a prison. The maximum on indictment is 2 years.

    Source: Psychoactive Substances Act 2016, s.9

  3. 3. How does s.74 of the Sexual Offences Act 2003 define consent for the purposes of Part 1 of the Act?

    1. A. A person consents if a reasonable person in the defendant's position would have believed he or she agreed
    2. B. A person consents if he agrees by choice, with the freedom and capacity to make that choice
    3. C. A person consents if he or she does not physically resist or otherwise signal a refusal
    4. D. A person consents if he or she is aged 16 or over and does not voice any objection at the time
    Show answer

    B. A person consents if he agrees by choice, with the freedom and capacity to make that choice

    Section 74 of the Sexual Offences Act 2003 provides that a person consents if he agrees by choice, and has the freedom and capacity to make that choice. Submission is not the same as consent, and a lack of resistance does not show agreement. Whether the defendant reasonably believed in consent is a separate element of each offence.

    Source: Sexual Offences Act 2003, s.74

  4. 4. Police executing a warrant at ADAMSON's house in England find a modern knuckleduster in his bedside drawer. He has never taken it outside. He does not claim it has any historical, museum, educational or theatrical purpose. Which is correct?

    1. A. ADAMSON commits an offence only if he intended to sell or hire it, as private possession is not an offence.
    2. B. ADAMSON commits no offence, because a knuckleduster is caught only when it is taken into a public place.
    3. C. ADAMSON commits an offence under s.141(1A) CJA 1988 of possessing a listed weapon in private.
    4. D. ADAMSON commits an offence under s.1 of the Prevention of Crime Act 1953, as it is made for causing injury.
    Show answer

    C. ADAMSON commits an offence under s.141(1A) CJA 1988 of possessing a listed weapon in private.

    Section 141(1A) makes it an offence to possess in private a weapon to which s.141 applies. In England and Wales 'in private' means anywhere other than a public place, school or further education premises, or a prison (s.141(1C)). A knuckleduster is listed in the Schedule to the Criminal Justice Act 1988 (Offensive Weapons) Order 1988 (antiques, broadly over 100 years old, are excluded), so possession of a modern one at home is an offence unless a statutory defence applies.

    Source: Criminal Justice Act 1988, s.141(1A) and (1C)

  5. 5. On a charge of murder, who bears the burden of proving diminished responsibility, and to what standard?

    1. A. The judge decides it as a question of law on medical evidence
    2. B. The prosecution, beyond reasonable doubt, once the defence raises it
    3. C. The defence, on the balance of probabilities
    4. D. The defence, beyond reasonable doubt
    Show answer

    C. The defence, on the balance of probabilities

    Section 2(2) Homicide Act 1957 provides that on a charge of murder it is for the defence to prove that the accused is not liable to be convicted of murder by reason of diminished responsibility. Where the burden is on the defence, the standard is the balance of probabilities, as the CPS guidance confirms.

    Source: Homicide Act 1957, s.2(2)

  6. 6. XENA, a door supervisor, puts a customer in a chokehold to remove him from a nightclub. There is no domestic relationship between them, and the customer suffers no visible injury. Which of the following is correct regarding s.75A SCA 2015?

    1. A. The offence cannot apply, because no injury was caused
    2. B. It can apply: it needs no injury and is not limited to domestic abuse
    3. C. The offence can apply only if the customer lost consciousness, however briefly
    4. D. The offence cannot apply, because it is confined to cases involving domestic abuse
    Show answer

    B. It can apply: it needs no injury and is not limited to domestic abuse

    The CPS guidance stresses that s.75A applies to all cases, not just those involving domestic abuse, and should be considered wherever there is evidence of strangulation or suffocation. A chokehold or headlock is a recognised method of strangulation, and no injury is required. Whether any force used was lawful (for example reasonable force to remove a trespasser) would be a separate question.

    Source: Serious Crime Act 2015, s.75A; CPS Strangulation and suffocation guidance

  7. 7. Following R v Barton and Booth, which of the following correctly describes how dishonesty is decided in theft where s.2 of the Theft Act 1968 does not apply?

    1. A. Dishonesty is a question of law for the judge, decided by reference to the definitions in s.2
    2. B. The jury first find the defendant's actual knowledge or belief as to the facts, then decide whether his conduct was dishonest by the standards of ordinary decent people
    3. C. The jury apply the defendant's own standards of honesty, provided his belief that his conduct met those standards was genuinely held
    4. D. The jury decide whether the conduct was dishonest by the standards of ordinary decent people, and then whether the defendant realised it was dishonest by those standards
    Show answer

    B. The jury first find the defendant's actual knowledge or belief as to the facts, then decide whether his conduct was dishonest by the standards of ordinary decent people

    In Ivey v Genting Casinos, approved for criminal cases in R v Barton and Booth, the tribunal first ascertains, subjectively, the actual state of the defendant's knowledge or belief as to the facts. It then decides whether his conduct was dishonest by the objective standards of ordinary decent people. The second limb of the old Ghosh test, whether the defendant realised his conduct was dishonest by those standards, no longer applies.

    Source: Theft Act 1968, s.2 (Ivey v Genting; R v Barton and Booth)

  8. 8. MERRICK fails to surrender to his bail at the magistrates' court and is charged with an offence under s.6(1) Bail Act 1976. Which of the following is correct?

    1. A. The offence can be committed only in relation to bail granted by a court, not by the police.
    2. B. It is for MERRICK to prove that he had reasonable cause for failing to surrender.
    3. C. Not having been given a copy of the bail record would be a reasonable cause.
    4. D. The prosecution must prove beyond reasonable doubt that he had no reasonable cause.
    Show answer

    B. It is for MERRICK to prove that he had reasonable cause for failing to surrender.

    A person released on bail in criminal proceedings who fails without reasonable cause to surrender to custody commits an offence (s.6(1) Bail Act 1976); it is also an offence, having had reasonable cause, to fail to surrender as soon after as reasonably practicable (s.6(2)). The accused must prove reasonable cause (s.6(3)), and failure to give him a copy of the bail record is not reasonable cause (s.6(4)).

    Source: Bail Act 1976, s.6(1)-(4)

  9. 9. The officer in charge of an investigation reasonably believes there is sufficient evidence to provide a realistic prospect of convicting VEALE, a detained suspect. What does Code C require the officer to do?

    1. A. Inform the custody officer without delay, as the custody officer is responsible for considering charge.
    2. B. Refer the case to a superintendent to consider extending VEALE's detention so that further enquiries can be made.
    3. C. Charge VEALE personally at the end of the interview and then inform the custody officer.
    4. D. Continue interviewing VEALE until he has been given the chance to admit the offence on tape.
    Show answer

    A. Inform the custody officer without delay, as the custody officer is responsible for considering charge.

    Code C para 16.1 provides that when the officer in charge reasonably believes there is sufficient evidence to provide a realistic prospect of conviction, they must inform the custody officer without delay, who is responsible for considering whether the detainee should be charged in line with the DPP's Guidance (para 16.1A). Para 11.6 requires the interview to stop at that point.

    Source: PACE Code C (2023), paras 11.6, 16.1-16.1A

  10. 10. A campaign group plans a march through a town centre to publicise its cause. Advance notice is reasonably practicable. Which is correct regarding notice under s.11 of the Public Order Act 1986?

    1. A. Notice may be given orally or in writing to the chief officer of police at least 6 clear days before the march.
    2. B. Written notice must be given to the local council, rather than the police, at least 28 days before the march.
    3. C. No notice is needed unless more than 20 people are expected, as smaller marches are exempt from s.11.
    4. D. It must be in writing, delivered to a police station in the area where it starts, normally 6 clear days before.
    Show answer

    D. It must be in writing, delivered to a police station in the area where it starts, normally 6 clear days before.

    Section 11(1) requires written notice of a public procession intended to demonstrate support for or opposition to views, publicise a cause or campaign, or commemorate an event, unless advance notice is not reasonably practicable. Section 11(4)-(6) requires delivery to a police station in the area where the procession will start, not less than 6 clear days before (by recorded delivery or by hand).

    Source: Public Order Act 1986, s.11

Frequently asked questions

+How long does it take to become a detective?

On the detective degree holder entry programme, about two years from joining. On the internal route, you first complete your probation as a uniformed constable (two to three years, depending on your entry route), then spend roughly a year or more as a trainee detective passing the NIE and completing PIP2.

+Do you need a degree to become a detective?

You need a degree in any subject for the detective degree holder entry programme. You don't need one to become a detective through the internal route: you join as a constable through any entry route your force offers, then apply for a trainee detective post after probation.

+What is the difference between a detective and a police officer?

A detective is a police officer. Detective constables hold the same rank and powers as uniformed constables, but they work in investigative roles and are accredited at PIP2 to handle serious and complex investigations.

+How much does a detective constable earn?

Detective constables are paid on the national constable scale. From 1 September 2025 it ran from £31,164 to £50,256, and the 2026 award added 3.5% from 1 September 2026. Overtime and London allowances come on top where they apply.

+What exam do you take to become a detective?

The National Investigators' Exam (NIE), run by the College of Policing. It has 80 multiple-choice questions in two hours, marked out of 70, on parts 1 to 4 of Blackstone's Police Investigators' Manual. In 2026 the pass mark was 55.7% (39 of 70).

+Can police staff become detectives?

Police staff can become accredited PIP2 investigators and sit the NIE, but the title detective constable belongs to warranted officers. Many forces employ police staff investigators in roles such as fraud, safeguarding and volume crime.

+What is a trainee detective constable?

A trainee detective constable (TDC) is a constable in an investigative post who is working towards PIP2 accreditation. They pass the NIE, complete their force's investigator development course and build a portfolio of evidence before being signed off.

Revision aid, not legal advice. The College of Policing exams follow the 2027 Blackstone's Police Manuals, so check every point against your manual and the current law on legislation.gov.uk. Police Sergeant Exam is independent and not affiliated with the College of Policing, the Home Office or Oxford University Press.

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