Lie Detector - Truth Verification

Computer Voice Stress Analyzer CVSA
lie detection truth verification

No wires attached, less stress and more effective that the polygraph!

The Computer Voice Stress Analyzer (CVSA) only uses a microphone that's plugged into the computer to analyze the person's responses. As the individual speaks, the computer displays and numbers each voice pattern and saves each chart to a file.

The CVSA program in and of itself Isn't a lie detector machine. The CVSA automatically analyzes the recorded yes or no responses to questions and detects deceptive or truthful reactions. 

Unlike the polygraph test, drugs don't affect the results of the exam, and there are no known countermeasures that will cause the typical "inconclusive" results associated with the polygraph.

A Voice Scanner CVSA lie detector test can be administered in the comfort of your home, office or via telephone by one of our experienced associate interviewers who will conduct the test. 

Thereafter, and in most cases, the examiner will use the CVSA program

to analyze the responses same day and provide a detailed report of the results same or next day.

Truth verification is just a phone call away!

Video - How CVSA Works

Check out the CVSA video!

The Examiner

H.J. Bennigson C.V.S.A. Examiner

Mr.  Bennigson has performed over 3000 CVSA’s, closed cases, obtained confessions and cleared individuals accused of crimes. He organized and planned recertification courses for all CVSA examiners throughout west coast. 

He works closely with several private attorneys and police departments for pre-employment, criminal and civil CVSA exams, and has over 34 years of law enforcement extensive training and experience as a supervisorial police officer, detective, hostage-crisis negotiator and expert witness.

CVSA leadership:

- Vice President – Western Association of CVSA

- President – Pacific Association of CVSA

- Director National association NACVSA

As President of the CVSA association and continuing board member, Mr.  Bennigson has met and developed a good working relationship with many law enforcement officials and department heads. He has personally met and successfully negotiated with State Legislators to lobby for the CVSA.


L.E. Awards:

- Good conduct medal 

- Life saving medal   

- Nominated for medal of courage 


C.V.S.A Study by James L. Chapman

Professor James L. Chapman CVSA Study


                                                Synopsis of CVSA Study                 


                                       Criminalistics and Court Expertise 

                                        2012 Annual Edition, Number 57 

                                  James L. Chapman, Professor Emeritus 

                             Former Director of Forensic Crime Laboratory 

                           State University of New York at Corning, NY USA 

                                                          Marigo Stathis 

                                  Scientific Consultant, Research Analyst 


                              (VOICE STRESS ANALYSIS) TECHNOLOGY 

                                  IN A US CRIMINAL JUSTICE SETTING  


This field study of criminal suspects and persons of interest is based upon actual CVSA examinations conducted by Prof. James Chapman over an 18-year period. The study resulted in an accuracy rate of 99.69%, a precision rate of 99.67% and a verified confession rate of 96.4%. 

The total inventory of CVSA cases submitted, which exceeded 3,000, was culled for cases that met the following criteria: 

•  A confession was a potential outcome 

• There was no involvement with veracity testing of previous statements •     

   No employment clearance was involved 

• The case was not used as confirmation of prior witness


• The facts of the case were such that responses could be verified by 

   means of CVSA follow-up questioning 

After excluding cases that did not meet all of the above criteria, the criminal cases remaining for study in which legally admissible confessions were possible totaled 2,109. A total of 236 cases, involving 329 specific crimes (“Confession Possibilities”), were randomly selected. These crimes included, but were not limited to: multiple homicides, corporate theft, organized crime, contract murders, sexual abuse of children, and arson for hire. 

The subjects examined represented a wide spectrum, from people with no criminal history to those with previous arrest/conviction records, and included both males and females. The socio-economic strata ran the gamut from wealthy, well-educated - 1 - Synopsis of CVSA Study professionals to indigents. The livelihood of those within the study group ranged from elected public officials to professional criminals, such as organized crime hit-men. 

Of the cases studied, 91% represented criminal investigations in which legal authorities had reached an investigative impasse. In other words, after following standard investigative procedures, investigators had been unable to reach a firm conclusion as to guilt or innocence. 

Each subject named in the “Confession Possibility” list was individually interviewed by the CVSA examiner, with two goals in mind: 

• To exonerate the innocent or identify the guilty, and 

• To obtain legally valid and independently verifiable confessions from   

   those subjects who were unable to clear the CVSA process. 

Each interview was conducted according to a standard protocol in which the wording of the interview, but not the methodology, was adapted on-site to each specific case. In each case, the CVSA procedure used by the examiner consisted of the following six steps:  

1. The CVSA examiner was briefed by the requesting authorities in order 

     to become familiar with the circumstances of each case. 

2.  A pre-test interview with the subject was conducted. 

3. The initial test questions were formulated and presented to the   

     subject. Examinations contained from 9 to 31 questions, consisting of     

     relevant, irrelevant, and control questions for which the subject   

     provided “yes” or “no” answers. 

4. The fourth step included processing the responses with the CVSA 

     instrument, after which the resulting CVSA charts were analyzed and 

     interpreted by the examiner. 

5. If stress patterns associated with specific relevant questions (those 

    questions pertinent to the crime) were observed by the examiner, an 

    opportunity was given for the subject to provide additional 

    clarification regarding the stress. Prior to the reexamination, questions 

    were reformulated by the examiner to evaluate the veracity of the 

    explanations offered by the subject. This procedure was repeated until 

    all necessary questions had received responses which displayed no 

    stress reaction or until the remaining stress reactions could not be 

    eliminated by the explanation or the re-questioning. 

6. The final step of the process was to provide a conclusion regarding the 

    outcome of the CVSA examination. If the relevant questions produced a 

    “No Stress” chart, the - 2 -  Synopsis of CVSA Study subject was 

    “cleared” by the CVSA procedure. This information was then turned 

    over to the agency requesting the examination. 

If a confession was made by the subject during the CVSA examination, the examiner would ask the subject to support his/her confession by verifying details or by providing further details concerning the events under investigation. Further, if a confession occurred, the subject was asked to provide a written statement. 

Another CVSA examination would then be conducted to validate the accuracy of the written statement. If no confession occurred, the examiner reported the findings to the agency requesting the CVSA examination, such that the information could guide further investigation. 

Of the 329 confession possibilities in this study, 92.1% of the CVSA examinations produced a “Stress Indicated” result, and 89% of those resulted in validated confessions. Most notably, in 96.4% of interviews conducted, where the CVSA indicated stress, suspects made self-incriminating confessions. 

The results of this study clearly establish that CVSA is a useful tool in obtaining valid confessions, and that the likelihood of obtaining valid confessions increases based upon whether or not stress is present for relevant crime issues. In each of the 236 cases in the study, which included 329 confession possibilities, a trained and experienced CVSA examiner used well-established CVSA protocols resulting in legally admissible confessions and the acquisition of additional supporting evidence from suspects and/or persons of interest. 

It is interesting to note that current scientific research reveals only 20-50% of police interviews/interrogations result in valid confessions. A 96.4% verified confession rate is phenomenally high compared to the 20-50% rate currently achieved by police. Further, during this study the CVSA had a negligible error rate, with a False Negative rate of 0% and a False Positive rate of 0.33%. 

More importantly, this study substantiates the CVSA is a useful and predictive decision support tool for separating the innocent from the guilty, and conclusively demonstrates the CVSA’s ability to discriminate stress from no-stress in the human voice. 

In one case of Grand Larceny 20 individuals were considered suspects. Of the 20 CVSA examinations conducted for this case, 19 resulted in a finding of “No Stress Indicated,” while only one produced a “Stress Indicated” finding – which resulted in a confession. CVSA demonstrated its capability to accurately identifying the 19 innocent individuals from the one who was guilty, far surpassing a “chance” rate of accuracy. The probability of 20 successful evaluations of this type is less than 1 in 1,000,000.