A Guide to Police Investigation: Understanding Your Rights

Being arrested or placed under a police investigation is often a confusing and stressful experience. Many people simply do not know what the police are allowed to do, how long the process can take, or what rights they have during questioning and detention.

Understanding your rights during a police investigation is crucial, not only to protect yourself but also to ensure the police act lawfully and follow the correct procedures. This comprehensive guide explains what you can expect at each stage of the police process, from arrest to interview and beyond, and sets out the steps you can take if your rights are breached.

When can the police arrest me?

The police can only arrest you if they have reasonable grounds to suspect that you are involved in a criminal offence and that an arrest is necessary. This is known as the PACE necessity test, and it ensures that the police cannot arrest people without proper justification.

An arrest may be considered necessary if:

• You refuse to give your name or address.
• The police believe you may abscond.
• They need to prevent harm, loss, or further offending.
• They need to investigate the offence effectively.
• They need to protect a vulnerable person or a child.
• To prevent an offence against public decency.
• If there is an unlawful obstruction to the highway.

If the arrest is not necessary, for example, if you agree to attend an interview voluntarily, the police should not arrest you. An unnecessary or unlawful arrest may give rise to a claim for false imprisonment or police misconduct.

To read more about the necessity to arrest, read our article explaining this.

What is the police arrest process?

If you are arrested, the police must follow strict procedures to ensure your arrest is lawful. The arrest process usually involves:

• Informing you that you are under arrest.
  
• Telling you the grounds for the arrest, what offence they believe you have committed.
  
• Cautioning you with the standard police caution:
   “You do not have to say anything, but it may harm your defence if you do not mention when questioned something which you later rely on in court. Anything you do say may be given in evidence.”
  
• Taking you to a police station for processing and detention (if required).

Once at the station, your personal details will be recorded, and you may be searched. You will also be assessed for health needs, vulnerabilities, or the need for an appropriate adult.

If these steps are not followed correctly, this may indicate that the arrest was procedurally flawed or unlawful. Read more details about the correct police procedure for arresting someone here.

What are my rights when under arrest?

Being arrested does not mean you lose your fundamental rights. You are legally entitled to:

• Free legal advice: You can speak to a solicitor privately before answering any questions.
  
• A copy of the Codes of Practice (PACE Codes): These outline how police must treat you.
  
• Notification of someone of your choice: You can ask the police to inform a friend or family member of your detention.
  
• Medical treatment if needed.
  
• An appropriate adult if you are under 18 or considered vulnerable.
  
• Food, drink, rest, and toilet facilities at reasonable intervals.

The right to legal advice is one of the most important protections you have. You should always speak to a solicitor before answering any police questions, even if you believe you have done nothing wrong. A solicitor can advise you on how to protect yourself and avoid self-incrimination.

How long can the police detain me?

There are strict limits on how long the police can detain you without charging you:

• Up to 24 hours for most offences.
  
• Up to 36 hours if a senior officer authorises an extension.
  
• Up to 96 hours for serious offences with magistrates’ approval.
  
• Up to 14 days under terrorism legislation (rare and only for terrorism cases).

During detention, the police must review the necessity and lawfulness of keeping you in custody at regular intervals. If they fail to release or charge you within the legal time limits, your detention becomes unlawful.

What should happen during a police interview and investigation?

A police interview is a key part of the police investigation process. It must follow strict rules to ensure fairness and lawfulness.

Before the interview begins, you must be:

• Informed of the allegations against you.
• Cautioned correctly.
• Offered free legal advice.

During the interview:

• The interview must be recorded.
• You must be allowed breaks.
• You must not be threatened, intimidated, or pressured.
• Any vulnerabilities must be taken into account.

The police investigation continues even after the interview. Officers may take witness statements, gather CCTV, obtain forensic evidence, and consult the Crown Prosecution Service (CPS) before deciding whether to take further action.

If the police decide not to charge you immediately, you may be:

• Released on bail, or
  
• Released under investigation (RUI) — meaning the investigation continues while you remain at liberty.
  
  

What are my rights when under police investigation?

Whether you are under investigation following arrest, voluntary attendance, bail, or RUI, you still have important rights. These include:

• The right to legal representation throughout the investigation.
  
• The right not to self-incriminate you do not have to answer every question.
  
• The right to be kept informed about the progress of your case.
  
• Protection from harassment or excessive delay.

Police investigations must be conducted fairly and without unnecessary delay. While there is no fixed legal time limit for investigations, they must remain proportionate and reasonable. Excessively long investigations may amount to misconduct or breach of duty.

How long does the police investigation process take?

There is no single answer to how long a police investigation takes. Some investigations conclude within days, while others can take months or even years. The duration depends on:

• The seriousness or complexity of the allegations.
  
• The availability of key evidence.
  
• Forensic processing times.
  
• Witness cooperation.
  
• CPS involvement.

If you are released on bail, the police must regularly review your bail status. If you are released under investigation, there is currently no statutory time limit, which has led to some individuals being left in limbo for long periods.

If you feel your case is dragging on unreasonably, you should seek legal advice. Excessive delays may breach your rights and could result in a claim for police misconduct or malicious prosecution if the investigation is mishandled.

What to do if your rights are breached by police

If you believe the police have breached your rights, whether through unlawful arrest, excessive detention, failure to follow proper procedures, or misconduct during an interview or investigation, you may be able to seek compensation.

Examples of police breaches include:

• Arresting you without reasonable grounds.
  
• Holding you in custody beyond the legal limits.
  
• Denying you access to legal advice.
  
• Conducting interviews unfairly or unlawfully.
  
• Failing to follow safeguarding requirements for vulnerable individuals.
  
• Mishandling evidence or acting in bad faith.

Depending on the circumstances, you may be able to pursue:

• A police complaint,
  
• A civil claim for compensation,
  
• A false imprisonment claim,
  
• A misfeasance in public office claim, or
  
• A breach of human rights claim.

Acting quickly is important, as strict time limits apply to different types of claims.

HNK Solicitors can help with your action against the police claim

At HNK Solicitors, we specialise in actions against the police and have extensive experience helping clients challenge unlawful arrests, excessive detention, and police misconduct during investigations.

Our expert team can:

• Review your arrest and investigation records.
  
• Advise you on whether the police acted unlawfully.
  
• Help you make a complaint or pursue a claim.
  
• Seek compensation for injustice, distress, or loss.
  
• Represent you on a no-win, no-fee basis where appropriate.

If you believe your rights were breached during a police investigation, you do not have to deal with it alone. Contact HNK Solicitors today for free, confidential advice and take the first step toward holding the police accountable. Call our team on 0151 668 0814 or email enquiries@hnksolicitors.com.