Fraud Investigation 101: Evidence, Interviews, and Ethics—What Employers Expect

Fraud investigation is not “catching someone.” It’s a disciplined process: preserve evidence, test hypotheses, document facts, and act ethically even when pressure is high.

If you want to be taken seriously as an investigator, these are the core skills you must demonstrate.

1) Evidence first (before opinions)

In real cases, the biggest risk isn’t missing the fraud—it’s contaminating evidence or creating documentation that doesn’t hold up.

A basic evidence hierarchy:

• System logs / audit trails
• Emails and approvals (metadata matters)
• Invoices, purchase orders, delivery proofs
• Bank/payment records
• Access logs and user activity

Rule: If it isn’t recorded, it didn’t happen (in an investigation report).

2) Chain of custody (simple but critical)

Chain of custody means you can prove:

• What evidence was collected
• When it was collected
• Who handled it
• Where it was stored
• Whether it was modified

Even in corporate investigations, this discipline protects the organization.

3) Interviewing: do it the smart way

Investigation interviews are not interrogations. A standard approach:

• Start with neutral fact gathering
• Confirm timeline and responsibilities
• Present inconsistencies calmly
• Let the subject explain
• Document responses accurately

Avoid:

• Leading questions that “plant” answers
• Threats or promises
• Emotion-driven accusations

4) Ethics: the part most people underestimate

A lot of investigators damage cases by:

• Sharing information informally
• Investigating beyond authority
• Allowing conflicts of interest
• Writing biased reports

Ethics is not “nice behavior.” It’s legal and reputational protection.

Mini case: Expense fraud (common, but tricky)

Red flags might include:

• Repeated reimbursements just under approval limits
• Same vendors used by multiple employees
• Weekend/holiday claims that don’t match work activity
• Missing supporting documents

An ethical investigator doesn’t jump to conclusions. They test explanations, verify documents, and document facts.

How SSDA trains investigators

The Certified Fraud Investigation & Ethics Specialist (CFIES) program focuses on practical capability:

• Evidence handling and report writing
• Interview frameworks
• Ethics under pressure
• Realistic case scenarios (not theory-only)

Related programs you can link at the bottom:
CFIES • AML & Financial Crime Compliance Analyst • CAPDA Pro (data-led investigations)