Vulnerable Witness Interviewing and Evidence Quality Training Course

Programme Summary

Vulnerable witness interviewing is the subject of this one-week training course for senior investigators and public protection leaders, ending in a witness interview quality protocol for use in their own services. Statements from children, victims with disabilities and intimidated witnesses are often central evidence, yet poor questioning can make them unusable. The programme moves from principles of memory and rapport, through diagnosis of interview failures, to the design of interviews and support measures, and then to application. Mars Training Centre UK delivers this vulnerable witness interviewing programme for leaders from mixed organisations.

The Business Case

An interview with a vulnerable witness is usually held once, often recorded, and later examined by prosecutors, defence lawyers and courts. Leaders are accountable for whether that account can be relied upon. Poor questioning contaminates memory, and weak records invite challenge. A consistent, rights-based process protects both witness and case.

• Evidence Reliability: Improves as questioning avoids suggestion and accounts are recorded in the witness's own words.
• Case Attrition: Falls as fewer interviews are challenged or excluded for avoidable process faults.
• Witness Welfare and Cooperation: Strengthens as support needs are assessed early and witnesses stay engaged through proceedings.

Principles and Evidence Base

• The PEACE model of investigative interviewing: Its five stages give the interview structure practised in Sessions 3 and 4.
• The Mendez Principles on Effective Interviewing for Investigations and Information Gathering: This international baseline favours rapport over coercion and frames the ethical tests in Sessions 1 and 2.
• Cognitive interview techniques and free recall: These memory-based methods shape how open prompts are sequenced in Session 3.

Intended Participants

• Investigation leaders who direct witness interviews with children and adults at risk.
• Heads of public protection who decide how support needs are assessed and recorded.
• Prosecution liaison leads who judge whether an interview will withstand legal scrutiny.
• Supervisors who review recorded interviews.
• Senior managers who own interview policy and training.

Relevant functions include policing, prosecution services, child protection and social care, and victim support agencies.

Learning Outcomes

1. Participants will be able to evaluate the reliability risks in an account obtained from a child, a person with a disability or an intimidated witness.
2. Participants will be able to diagnose planning, rapport and questioning faults in recorded interviews.
3. Participants will be able to construct an interview plan that applies the PEACE model to a defined witness need.
4. Participants will be able to justify the choice of support and protective measures for a witness.
5. Participants will be able to prioritise the quality checks that make a recorded interview defensible.
6. Participants will be able to design a review routine that raises interviewing standards.

Programme Structure

Day 1: Vulnerability, Memory and Rights-Based Interviewing

Why do some witnesses give accounts that cannot be relied upon?

• Mendez Principles Ethical Tests
• Memory and Suggestibility Principles
• Witness Vulnerability Categories
• Trauma and Communication Needs Profile
• Evidence Reliability Risk Map

Day 2: Diagnosing Interview Failures and Evidence Weaknesses

Where do interviews lose accuracy, completeness or credibility?

• Leading Question Audit
• Rapport Breakdown Indicators
• Interview Record Gap Analysis
• Contamination and Pre-Interview Contact Review
• Witness Support Needs Assessment Sheet

Day 3: Designing the Interview with the PEACE Model

How is an interview planned so that the witness can give a full account?

• PEACE Planning and Preparation Template
• Engage and Explain Script
• Free Recall and Open Prompt Sequence
• Cognitive Interview Techniques
• Account Clarification Question Bank

Day 4: Support, Protective Measures and Recording Practice

How are support and recording arranged so that the account stands up later?

• Protective Measures Decision Matrix
• Communication Aid and Intermediary Briefing
• Recorded Interview Setup Checklist
• Closure and Evaluation Record
• Interview Quality Scoring Grid

Day 5: Applying Vulnerable Witness Interviewing Standards to Live Practice

Is the quality protocol ready to govern interviews in your own service?

• Applying the Session 1 Ethical Tests to Local Practice
• Testing the Session 2 Failure Indicators on Sample Interviews
• Finalising the Session 3 Interview Plan Template
• Adopting the Session 4 Decision Matrix and Scoring Grid
• Completing the Witness Interview Quality Protocol

Methodology

The programme uses a structured exercise method built on anonymised interview scenarios and recorded extracts. Participants plan interviews, critique extracts against agreed criteria and practise feedback in small groups, receiving facilitator and peer comment on each work product before it enters the quality protocol.

• Suggested activity: Rewriting a set of leading questions into open prompts and comparing the accounts each would draw out.
• Suggested activity: Scoring an anonymised recorded interview with the quality grid and reconciling scorer differences.
• Suggested activity: Planning an interview for a witness with a communication difficulty and defending the support choices.

Capstone Output

Each participant completes a witness interview quality protocol for their own service. It holds an ethical test list, a support needs sheet, an interview plan template, a decision matrix, a quality scoring grid and a supervisor review routine. It is used at work to plan and supervise interviews.

Frequently Asked Questions

Is vulnerable witness interviewing suitable for leaders who do not conduct interviews themselves?

Yes. Vulnerable witness interviewing is taught for those who direct and supervise interviews, so hands-on experience is useful but not assumed.

Which models does vulnerable witness interviewing rest on in this programme?

Vulnerable witness interviewing here rests on the PEACE model, the Mendez Principles on effective interviewing and cognitive interview techniques built on free recall.

How is the witness interview quality protocol from vulnerable witness interviewing used at work?

You use the protocol to plan interviews, set quality checks, supervise interviewers and show how each account was obtained and supported.

How does vulnerable witness interviewing differ from a programme on suspect interviewing?

Vulnerable witness interviewing centres on obtaining reliable accounts from witnesses with support needs, while suspect interviewing centres on testing an account given under suspicion.