Overview of the Polygraph

The polygraph is an investigative tool used by the police to assist investigators in criminal investigations.

A suspect must voluntarily submit to a criminal forensic test that takes approximately 3 hours to complete. All particpants in a polygraph examination are requested to sign a consent form.

The Medicine Hat Police Service utilizes the Lafayette LX 4000 computer based polygraph instrument. The instrument records changes in an examinee's breathing, galvanic skin response and heart rate.

The Medicine Hat Police Service also uses the polygraph to conduct pre-employment screening tests for potential employees such as police recruits, 9-1-1 dispatch personnel, civilian staff and photo radar employees.