For local authority investigators, interviewing is at the heart of effective casework. Interviews aren’t just fact finding conversations; they are a formal investigative tool with legal significance. The way you conduct them can determine whether your evidence stands up in court or during enforcement action. 

But good interviewing isn’t just about instinct or experience. It requires a clear understanding of the law, particularly the Police and Criminal Evidence Act 1984 (PACE), and a professional approach supported by structured techniques like the PEACE model (Planning and preparation, engage and explain, account, closure and evaluation). 

When interviews are handled lawfully and skilfully, they generate reliable evidence, support sound decision-making, and protect the public interest. When mishandled, they can result in inadmissible evidence, failed prosecutions, or reputational damage to your authority. 

PACE  

PACE isn’t just for the police. If your investigation might result in a criminal prosecution, PACE applies to you too. This includes interviews carried out under caution by local authority officers acting in their enforcement role; whether you’re interviewing a business owner suspected of misleading trading, a landlord accused of a housing offence or a shop keeper breaching licensing conditions. 

PACE protects the rights of suspects and ensures fairness in the gathering of evidence. The key provisions every local authority investigator must know include: 

Caution 
You must caution a person before asking questions if you suspect them of an offence and intend to use their answers in evidence. The standard caution reads: 
“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.” 

Using the wrong caution, or failing to use it when required, risks making the evidence inadmissible. 

Right to Legal Advice 
Under PACE, suspects have the right to free legal advice. You must make them aware of this right before the interview starts. Proceeding without making this clear can jeopardise your case. 

Recording Interviews (Code E) 
Local authority investigators must follow the rules for audio-recording interviews when interviewing suspects for indictable offences or where required by enforcement policy. Correct handling, sealing, and storage of recordings protect both you and the interviewee. 

Safeguarding Vulnerable People 
If the interviewee is under 18 or considered vulnerable (for reasons such as mental health or learning difficulties), an appropriate adult must be present during the interview. Failing to ensure this safeguard can invalidate the interview. 

Avoiding Oppression and Misconduct 
You must always act with integrity and fairness, even in difficult interviews. 

Any evidence obtained through threats, unfair pressure, or oppressive behaviour is likely to be excluded.  

PEACE 

While PACE sets the legal rules, PEACE (Planning and preparation, engage and explain, account, closure and evaluation) provides a practical structure for conducting effective, professional interviews in the regulatory enforcement context. 

Unlike formal suspect interviews under PACE, PEACE can also help structure fact-finding interviews with witnesses, business representatives, or those who may later become suspects. 

1. Planning and preparation: Successful interviews start long before you sit down with the interviewee. Good planning involves: 

• Clarifying your interview objectives. 

• Understanding the evidence you already have. 

• Deciding whether a caution is required. 

• Considering the need for legal advice or an appropriate adult. 

• Structuring your questions logically. 

Inadequate planning often leads to missed opportunities, legal errors or unreliable evidence. 

2. Engage and explain: Your professional approach is crucial. This includes: 

• Building rapport and explaining the purpose of the interview. 

• Clarifying rights and procedures, including the right to legal advice and, if relevant, explaining the caution. 

• Being neutral, objective, and professional throughout. 

Your approach can affect the cooperation of the interviewee and the credibility of the evidence obtained.  Experienced interviewers have suggested that there is a positive correlation between constructive interpersonal relationships between the suspect and the interviewer and a higher level of information given. 

3. Account clarification and challenge: This is the main part of the interview. This includes: 

• Starting with open questions, 

• Gaining the suspects explanation of what has happened in relation to the suspected offence. 

• Gradually asking more specific questions. 

• Using closed questions if required to obtain finer details. 

4. Closure: Closing an interview properly matters. You should: 

• Summarise key points with the interviewee. 

• Offer them the chance to clarify or add anything. 

• Explain what will happen next in the investigation. 

• Ensure all paperwork, recordings, and notes are accurate and complete. 

Closure isn’t just administrative; it helps protect the integrity of the investigation. 

5. Evaluation: After the interview, critically assess what happened. Ask yourself 

• Did I meet my objectives? 

• Was the interview PACE compliant? 

• Has new information come to light requiring further action? 

• Are my records and recordings complete? 

The evaluation stage reinforces accountability and learning, helping you improve your practice and ensure evidential quality. 

Regulatory investigations often operate in complex legal and social environments. PACE protects the rights of individuals and the admissibility of evidence. PEACE helps you apply structure, professionalism, and investigative skill. Mastering both frameworks is key to investigative success. 

Training 

Interviewing is a professional skill, and like any skill, it needs regular practice and updating. 

• PACE Training: Make sure you’re familiar with the latest Codes of Practice, particularly around cautions, legal rights, and vulnerable interviewees. 

• PEACE Interview Skills: Keep refining your questioning techniques, planning, and post-interview evaluation. 

• Scenario-Based Practice: Realistic training scenarios help bridge the gap between theory and practice. 

Regular training not only sharpens your skills but demonstrates your authority’s commitment to lawful and effective enforcement. 

Act Now has a range of customised in house training courses on RIPA, PACE, investigations and interview techniques. Our associates include Naomi Mathews who is a Senior Solicitor and was a co-ordinating officer for RIPA at a large local authority in the Midlands. Naomi has extensive experience in all areas of regulatory law and investigations.  She has worked as a defence solicitor in private practice and as a prosecutor for the local authority in a range of regulatory matters including Trading Standards, Health and Safety and Environmental prosecutions. Naomi has higher rights of audience to present cases in the Crown Court. 

Get in touch if you would like a free 30 minute consultation to discuss your training needs.