The Union County Police Polygraph Unit, which works out of the department's Detective Bureau, runs polygraph examinations for all municipalities in Union County. The polygraph examination is primarily used by detectives to identify guilty suspects and to eliminate suspects who are truthful. Examinations are also conducted to verify the truthfulness of alibi witnesses and informants.

Each test, which can be conducted at any police department headquarters in Union County, takes approximately two (2) hours to conduct. There is added time to formulate questions, prepare various paperwork and chart analysis. Federal, State, and County Courts use polygraph examination results when proper criteria are met.