Investigations Plus Ltd prioritizes expert lie detection interviews over machine-based polygraph testing. While we offer both services, here’s why trained investigators consistently outperform equipment.

The Limitations of Polygraph Equipment

Polygraph machines measure physiological responses: heart rate, blood pressure, breathing patterns. They record stress, not dishonesty.

The problem? Polygraphs can be manipulated. Countermeasures work. The machine tracks physical reactions but misses the subtle indicators that reveal actual deception.

Our investigators catch what machines cannot:

• Automatic verbal responses that slip out before conscious filtering
• Linguistic patterns including pronoun shifts, tense changes, and excess detail
• Speech rhythm disruptions when moving between truth and fabrication
• Cognitive load indicators shown through hesitation and processing delays
• Deflection strategies used to avoid direct answers
• Emotional-verbal mismatches between stated feelings and actual presentation

When Expert Lie Detection Is Required

• Workplace investigations where employees decline polygraph testing or require ongoing assessment
• Infidelity cases demanding multiple conversations as details emerge
• Missing persons inquiries where witness statements contain inconsistencies
• Business due diligence requiring careful verification over extended discussions
• Custody disputes involving layered allegations needing thorough examination

Limited Applications for Polygraph

Polygraph testing has specific uses:

• Pre-employment verification where physiological baseline data serves administrative purposes
• Single-session screening when one-time results are contractually required
• Supplementary documentation where physical data adds to comprehensive evidence

Recognize its constraints. Practiced liars defeat polygraphs. Truthful subjects under stress fail them.

Why Choose Investigations Plus Ltd

Our investigators bring decades of training in behavioral analysis, forensic interviewing, and deception detection. We read complete human communication: verbal content, delivery patterns, and emotional consistency across time.

That beats measuring someone’s heart rate.

Unsure which service your case requires? Contact us for a confidential assessment.