The Polygraph Unit administers polygraph examinations to police applicants, suspects, victims, witnesses involved in Department investigations, and to Department personnel seeking a voluntary assignment to a specialized unit. The Polygraph Unit is comprised of civilian polygraph examiners – the majority being former law enforcement officers from various local and federal agencies.
In 2001, polygraph examinations became an additional requirement in the police officer applicant process and have proven to be a useful investigative tool in background investigations.
The polygraph exam is administered utilizing a computerized polygraph instrument to record physiological data from three systems of the human body. A typical polygraph examination will include a pre-test interview, a chart collection phase (in-test), a test data analysis phase, and a post-test interview/interrogation. The entire process takes approximately two to three hours. Polygraph exams may be administered to verify the truthfulness of information and/or to determine participation in a crime.
In 2010, the LAPD Polygraph Unit was the first state or local law enforcement agency in the United States to successfully complete the accreditation process through the Polygraph Law Enforcement Accreditation (PLEA) program.