Risk Management, Documentation, and Due Diligence

For Illinois law enforcement agencies, polygraph examinations are a structured investigative tool that supports documentation, credibility assessment, and liability mitigation.

Criminal Investigations

In criminal investigations, an Illinois law enforcement polygraph examination provides investigators with additional credibility data when evaluating suspects, witnesses, and involved parties. While no investigative tool stands alone, a properly conducted polygraph — administered using accepted testing formats and professional standards — can help clarify conflicting statements, narrow investigative focus, and document due diligence. It is structured credibility assessment that aids investigations.

Confidential Informant Confirmation and Liability Considerations

Few areas carry greater liability exposure than reliance on confidential informants (CIs). Informant credibility affects charging decisions, warrant applications, prosecutorial strategy, and overall investigative integrity. When agencies rely on uncorroborated CI statements, they assume risk — particularly if credibility is later challenged in court.

A properly administered polygraph examination provides an additional layer of credibility assessment and documentation. While it does not replace independent corroboration, it demonstrates that the agency took reasonable steps to evaluate the reliability of the information being provided. For municipal attorneys and command staff, this documentation supports defensible decision-making and strengthens the agency’s position when investigative actions are later scrutinized.

In Illinois criminal investigations, the ability to show that informant information was evaluated through structured procedures — including polygraph where appropriate — reflects professional due diligence.

Screening LEO Applicants

Hiring decisions create long-term organizational exposure. An Illinois police pre-employment polygraph examination is one component of a comprehensive background investigation that includes psychological evaluation, criminal history review, employment verification, and reference checks.

The purpose of a pre-employment polygraph is not to “catch” applicants, but to provide adjudicators with additional verified information. It allows agencies to:

• Clarify discrepancies in background disclosures

• Confirm or resolve integrity concerns

• Document admissions or inconsistencies

• Strengthen the defensibility of hiring decisions

When agencies can demonstrate that hiring determinations were made after structured background review — including polygraph screening — they reduce avoidable liability and support sound governance.

A Professional Standard for Illinois Agencies

In today’s era of policing: where liability and professional accountability are significant considerations, agencies must be deliberate about who they hire. A properly administered polygraph examination is one component of a comprehensive background investigation designed to reduce risk and strengthen defensibility. It is not a standalone decision-maker, but it is an important layer in ensuring integrity before authority is granted.