Most employers have policies permitting them to conduct searches of employees and their property. And, if done right, those policies are necessary and useful. If you suspect an employee of committing theft or coming to work under the influence of drugs or alcohol, the best way to confirm this suspicion often is to conduct a search.
However, public sector employers can quickly run into problems with such policies if they are not devised with knowledge of the law. Unlike private-sector employers, government employers are bound by the Constitution. That includes the Fourth Amendment with its prohibitions against searches and seizures without a warrant.
With that said, public sector employers have much more leeway when conducting employee searches than, say, the police when they attempt to search someone’s home. Employers in the public sector can conduct searches of an employee and his or her workspace if that employee does not have a reasonable expectation of privacy in that workplace and the employer has a good reason to conduct the search. For example, it would not be a Fourth Amendment violation for an employer to search an employee’s file cabinets or office if many people access the file cabinet and office. The expectation of privacy in these spaces is low.
However, it would be a Fourth Amendment violation for a government employer to randomly search non-work-related items that the employee brings into the office. So, if the employee was leaving for the airport after work and brought a suitcase into the office, it would be a Fourth Amendment violation for the employer to search the suitcase without a very good reason. The employee has a high expectation of privacy in the suitcase, and in most circumstances, there would be no work-related need to search it.
Government employers need to keep this in mind when drafting search policies. Policies that permit the employer to search an employee’s bags, car, or personal mail on a whim almost certainly violate the Fourth Amendment. However, policies that permit the employer to search the employee’s desk, file cabinets, and office if there is a work-related reason for doing so almost certainly do not.
Knowing what searches are permitted and what searches are a Fourth Amendment violation probably takes consultation with a lawyer, so it is a good idea to contact an experienced local government attorney for questions about putting such a policy together.