NRS 331.220: Surreptitious electronic surveillance prohibited; exceptions.

1. Except as otherwise provided in subsection 2, it is unlawful for a person to engage in any kind of surreptitious electronic surveillance on the grounds of any facility owned or leased by the State of Nevada without the knowledge of the person being observed.

2. Subsection 1 does not apply to any electronic surveillance:

(a) Authorized by a court order issued to a public officer, based upon a showing of probable cause to believe that criminal activity is occurring on the property under surveillance;

(b) By a law enforcement agency pursuant to a criminal investigation;

(c) By a peace officer pursuant to NRS 289.830; or

(d) Which is necessary as part of a system of security used to protect and ensure the safety of persons on the grounds of the facility.