Private sector. Under California law, it is illegal for private sector employers to demand or require employees or applicants for employment to submit to a lie detector test. An employer may not administer a test or request that an employee or applicant take a test without first advising the person in writing that the test may not be required as a condition of employment or continued employment. This prohibition does not apply to the federal or state governments, or counties, cities, and districts (CA Lab. Code Sec. 432.2).
Public sector. No public safety officer may be compelled to take a lie detector test against his or her will. If a public safety officer refuses to take a lie detector test, the law forbids any retaliatory action against the employee for doing so. Also, neither the refusal to submit to the test can be referred to in an investigator's notes nor can the refusal be entered as evidence against the employee. “Lie detector test” means a polygraph, deceptograph, voice stress analyzer, psychological stress evaluator, or any other similar device, whether mechanical or electrical, that is used for the purpose of rendering a diagnostic opinion regarding the honesty or dishonesty of an individual (CA Gov. Code Sec. 3307).
Voice stress analysis. Voice stress analysis is prohibited for assessing the truth or falsity of a statement, unless the person who is subjected to the analysis has given his or her express written consent to the procedure in advance. The prohibition does not apply to peace officers while carrying out their official duties. Violators of this rule may have to pay actual damages or a fine of up to $1,000, whichever is greater (CA Penal Code Sec. 637.3.