National Investigator's Exam (NIE): Free Mock Test & Practice Questions

National Investigator's Exam (NIE)

This exam is taken by police officers and staff in England and Wales seeking to become accredited detectives. Passing the NIE is a mandatory step for entry into a Trainee Investigator (TI) or Detective Constable (DC) role.

Pass mark 45/80 120 minutes Real test fee approx College of Policing How many can I get wrong?

Little and often beats one big session. Five minutes on the bus counts.

Free practice questions

Try 3 real National Investigator's Exam (NIE) questions

Have a go, then reveal the worked explanation. A taster from a bank of 205 original questions — unlock for unlimited drills and full timed mocks.

Q1. A constable has reasonable grounds to suspect a person has committed an offence. To make a lawful arrest under Section 24 of PACE, what additional condition must be satisfied?

A. The offence must be indictable only.
B. The officer must have a warrant for the arrest.
C. The officer must believe the arrest is necessary for one of the reasons in PACE Code G.
D. The suspect must have been previously cautioned for a similar offence.

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✓ Answer: C. The officer must believe the arrest is necessary for one of the reasons in PACE Code G.

A lawful arrest requires both reasonable grounds for suspicion and a belief that the arrest is necessary. This is often referred to as the 'necessity test' (IDCOPPLAN).

Q2. An investigator is transporting a suspect to the police station following an arrest for burglary. The suspect suddenly says, "Okay, it was me, I needed the money." What is the most appropriate immediate action for the investigator to take?

A. Immediately caution the suspect again and ask them to repeat the comment for a body-worn video recording.
B. Make a written record of the comment in their pocket notebook at the earliest opportunity and ask the suspect to verify it.
C. Stop the police vehicle and conduct a full, PACE-compliant interview on the roadside.
D. Ignore the comment as it was not made during a formal interview and is therefore inadmissible.

Show answer & explanation

✓ Answer: B. Make a written record of the comment in their pocket notebook at the earliest opportunity and ask the suspect to verify it.

This is a significant statement. Under PACE Code C, it must be recorded, the time noted, and the suspect given an opportunity to verify its accuracy.

Q3. A woman enters a hospital ward as a trespasser with the sole intention of visiting a relative outside of visiting hours. Once inside, she sees an unattended wallet and spontaneously decides to steal it. Which specific offence has she committed?

A. Section 9(1)(a) Burglary
B. Section 9(1)(b) Burglary
C. Section 10 Aggravated Burglary
D. Theft

Show answer & explanation

✓ Answer: B. Section 9(1)(b) Burglary

Section 9(1)(b) Burglary is committed when a person, having entered a building as a trespasser, then steals or attempts to steal. The intent to steal was formed after entry.

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National Investigator's Exam (NIE) — common questions

Frequently asked

How many questions are in the National Investigator's Exam (NIE)?

The exam has 80 questions. Every Revision Robin mock uses the same 80-question format so your practice matches the real thing.

What is the pass mark for the National Investigator's Exam (NIE)?

You need 45 out of 80 correct to pass, which is about 56%. Our mocks mark you against this exact threshold.

How long do you get?

The test is timed at 120 minutes. Our full mock runs on the same clock so you can practise your pacing.

Are these the real exam questions?

No. Our questions are original and written to match the current syllabus, so they give realistic practice without copying the official paper. Every answer comes with a plain-English explanation. Always confirm current rules and content with College of Policing.

How much does the official test cost?

The official College of Policing fee is approx. Revision Robin practice is separate and helps you pass first time so you only pay that fee once.