E.P.P. 038
LONGWOOD POLICE DEPARTMENT
ENFORCEMENT POLICY & PROCEDURE
NUMBER: EPP – 38
SUBJECT: COMPUTERIZED VOICE STRESS ANALYZER (C.V.S.A.) TESTING
EFFECTIVE: OCTOBER 25, 2001
REVISED: JANUARY 1, 2023
ENFORCEMENT POLICY AND PROCEDURE
COMPUTERIZED VOICE STRESS ANALYZER (C.V.S.A.) TESTING
EPP – 38 Page 1 of 4
I. PURPOSE
It is the purpose of this directive to provide policy for the use of the Computer Voice Stress
Analyzer (C.V.S.A.).
II. SCOPE
The C.V.S.A. is an instrument designed to measure levels of stress in an individual’s voice
caused by psychological stimuli. This measurement is obtained in the form of a
physiological response to a question due to sub-audible frequency modulation in the
voice. The C.V.S.A. may be used at the time of an actual live examination, or a recorded
conversation may be analyzed at a later time.
III. GENERAL
The C.V.S.A. is an investigative tool and may be used in conjunction with other tools and
techniques available to the investigator. The results of a C.V.S.A. examination will not be
the sole determining factor to complete an investigation.
IV. PRIORITY OF C.V.S.A. EXAMINATIONS
Requests will be handled in a timely fashion and in accordance with the following
priorities:
A. Criminal Investigations (prioritized according to the seriousness of the crime);
B. Administrative investigations;
C. Pre-employment examinations; and,
D. Requests from other law enforcement agencies, upon approval by a supervisor.
ENFORCEMENT POLICY AND PROCEDURE
COMPUTERIZED VOICE STRESS ANALYZER (C.V.S.A.) TESTING
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V. REQUEST PROCEDURE
A. A request for an examination originating from a police officer may be generated
by any said officer, but must be approved by the officer’s supervisor.
1. A request for an examination should only be made when the officer
desiring the examination believes that the examination will have practical
application to his/her investigation.
2. All requests for examinations must be submitted by email to CVSA
Examiner and Criminal Investigations Supervisor.
B. A request for an examination for a pre-employment examination, may originate
directly from the Background Investigator.
C. All requests for the C.V.S.A. examination must be approved by Criminal
Investigations Lieutenant.
D. All requests shall be accompanied by a summary of the case involved and/or
pertinent questions to be resolved.
E. All requests pertaining to the examination of juveniles should be obtained by a
consent by the appropriate parent or guardian.
F. The above requirements apply to requests for analysis of either “real time” or
recorded interviews.
VI. SCHEDULING AN EXAMINATION
A. The C.V.S.A. examiner will be briefed on the case during a pre-examination
interview with the investigator. The intent of this briefing is to give the examiner
enough information to conduct a reasonable and accurate examination. Briefings
should include discussion about the original Offense Report, summary of the
case, the results of any transcribed statement, and pertinent questions the
investigator would like to have resolved.
B. The Investigator is responsible for:
1. Arranging an interview date and time between the examiner and the
examinee;
2. Remaining near the examination room while the interview is in progress;
3. Notifying the examiner as soon as possible if an appointment has been
cancelled.
ENFORCEMENT POLICY AND PROCEDURE
COMPUTERIZED VOICE STRESS ANALYZER (C.V.S.A.) TESTING
EPP – 38 Page 3 of 4
VII. PREVIOUSLY RECORDED INTERVIEWS
A. Under certain conditions, C.V.S.A. examination may be conducted on a previously
recorded interview. Before proceeding with such interview, the investigator
should contact the C.V.S.A. examiner for instruction about the proper structure
under which a recorded interview must be conducted.
B. The examiner asked to run the analysis will first listen to the recorded interview.
The examiner will then make a final determination as to whether a recorded
interview is of sufficient quality to perform an accurate analysis.
VIII. C.V.S.A. EXAMINER RESPONSIBILITIES
A. Training:
1. Examiners will be licensed for the use of the C.V.S.A. prior to conducting
any examinations. Examiners whose certification have expired or have
been revoked are prohibited from conducting examinations.
2. Unless relieved of the C.V.S.A. duty function, examiners will maintain
current certification and will retain records attesting to their
certification.
3. Initial training and current certification records will be maintained in the
examiner’s Training File.
B. Preparing for the Examination:
1. All examinations will be conducted in accordance with most recent
training.
2. An examiner will not participate (nor serve as the verifying secondary
examiner) in any examination that might compromise an investigation.
Examiners will not conduct examinations of friends, relatives, or any
person where a conflict of interest may arise.
3. The examiner will ensure that the following conditions are met prior to
the start of an examination:
a. Complete a C.V.S.A. Consent Form, if needed;
b. Access a good quality audio recorder or a video camera with
audio capability;
ENFORCEMENT POLICY AND PROCEDURE
COMPUTERIZED VOICE STRESS ANALYZER (C.V.S.A.) TESTING
EPP – 38 Page 4 of 4
c. When preparing the examination questionnaire, if possible,
prepare direct questions that solicit a simple “yes” or “no”
answer from the examinee;
d. Ensure that the recorder or microphone is close enough to the
examinee to clearly record their responses;
e. Ask the examinee to delay their answers one-two seconds to
avoid any “overlap” of the interviewer’s question with the
recorded response; and,
f. If recording a telephone conversation, ensure that the subject
speaks clearly into the mouthpiece. If a response is unclear,
repeat the question.
C. Post-Examination Procedures:
1. Based upon an evaluation at the conclusion of the examination, the
examiner will render a written opinion to the investigator.
a. A copy of the examiner’s report in a form of memorandum will
be forwarded to the investigator as soon as possible.
b. Reports will be written to highlight the questions that generated
responses consistent with deception.
c. Original records are available for public inspection (unless
specified otherwise by law) and will be retained by the requesting
investigator. The records will be retained for a period of time as
directed by the Records Management Division.