I am posting this question on behalf of another detective who posed it to the DFW Crime Analyst List Serve:

Does anyone know of a law that prohibits the use of surveillance cameras in restrooms? The Improper Video (PC 21.15) does not fit since the camera was not "recorded" and disorderly conduct does not fit because we can not prove the store owner "looked" at the monitor while someone was using the restroom. In this case a store owner had concealed a video camera in the lady's restroom and the camera was specificlly pointed under the stall door to the toilet. The camera was hooked up to a monitor but not a recorder.

TIA for always learned and informative responses.