Investigator Tips

Current Investigator Tip

Parental Abuse Interviews in Human Trafficking Investigations

Feb 03, 2021

Among the interviewing challenges faced by human trafficking investigators is the issue of parental abuse of a trafficking victim. How does an investigator approach this topic?

When suspicion arises that the...

Previous Tips

Consideration For an Investigator's Attire

Jan 01, 2005

The very first impression a subject forms of an investigator will be based on physical observations -- not only gender, race and body type, but also attire. The desired perception...

Issues to Consider Regarding Possible Suicidal Suspects

Nov 01, 2004

It was about 4:00 in the afternoon when one of our regular clients called and requested an "emergency" polygraph examination for a 19-year-old female employee they suspected was stealing jewelry from...

Testifying on a Suspect's Behavior Symptoms

Oct 01, 2004

Recently, the Washington Supreme Court reversed a rape conviction partially because the trial court admitted an investigator's testimony that the defendant's verbal and nonverbal behavior symptoms were indicative of guilt...

Selecting the Proper Alternative Question

Sep 01, 2004

The Reid Technique of interrogation relies on two important underlying psychological principles. The first is that it is much easier for a person to tell the truth if that person...

The Importance of Accurate Corroboration within a Confession

Aug 01, 2004

The Importance of Accurate Corroboration within a Confession

Of all possible evidence presented against a defendant at trial, a confession is afforded the most weight. Because of this, we have...

Interviewing Elderly Subjects

Jul 01, 2004

Interviewing techniques presented in textbooks or during seminars generally assume that the person being interviewed is an emotionally healthy and mature individual with a normal IQ. Twenty-five years ago, when...

Lying to a Suspect: How Far Can an Investigator Go?

Jun 01, 2004

During the course of an investigation an investigator often must rely on duplicity and pretense in an effort to develop evidence against the guilty suspect. Common examples include...

Investigating Possible Fabricated Claims

May 01, 2004

A recent case involving a University of Wisconsin student who falsely claimed that she was abducted highlights some important characteristics of these investigations. This particular case quickly achieved national attention...

False Confession Cases - The Issues

Apr 01, 2004

In the past several years a number of false confession cases have received extensive publicity. In several of these cases the convicted individual has been exonerated by DNA testing and the actual...

The Presence of a Third Person in the Interview Room

Mar 01, 2004

Ideally, an interview of a suspect, victim or witness should be conducted in a private setting. The most important element of privacy is communicating one on one with the person...

Willingness to Repay Stolen Funds Not Always An Indication of Guilt

Feb 01, 2004

During our basic interviewing and interrogation course, the point is made that during an interrogation a suspect's willingness to reimburse a victim for stolen money...

The Significance of Listing in Behavior Symptom Analysis

Jan 01, 2004

Listing, as a behavior symptom, describes a series of events or information included within a subject's response. In the following dialogue both of the subject's responses illustrate an...

Interrogating a Suspect on the Issue of Identity Theft

Dec 01, 2003

The Federal Trade Commission estimated that in 2002 identity theft cost businesses and consumers 53 billion dollars. Because of the prevalence of identity theft, many investigators find themselves having to interrogate...

Maintaining Objectivity During an Interview

Nov 01, 2003

An interview is designed not only to collect and gather information but to assess the credibility of the person offering that information. In some instances the investigator will...

Laughter and the Detection of Deception

Oct 01, 2003

Recently my wife and I attended her high school reunion. While such reunions are marketed as a great time and an opportunity to get re-acquainted, in truth they are very anxiety...

The Use of Evidence During an Interrogation: Part II

Sep 01, 2003

In the earlier web tip a fundamental principle of interrogation was presented: A guilty suspect may be persuaded to tell the truth if he is convinced that the investigator is...

The Use of Evidence During an Interrogation: Part I

Aug 01, 2003

Types of Evidence

Evidence represents information used to help establish a fact. It may be inculpatory (supporting guilt) or exculpatory (supporting innocence). There are four broad categories of criminal evidence, each with...

Contaminating a Subject's Behavior

Jul 01, 2003

When inferring deception from a suspect's behavior, investigators must remember that a subject's outward behaviors during questioning are not direct signs of lying. Rather, when a person lies behavior symptoms...

The Role Of Consequences in Detecting Deception

Jun 01, 2003

The motivation behind every lie is the avoid the consequences of telling the truth. When my wife came home with bags of merchandise from a K-Mart store that was...

Neurolinguistic Evaluation

May 01, 2003

Neurolinguistic Evaluation


The outer cortex of the human brain is divided into left and right hemispheres. When performing different activities, one hemisphere dominates over...