As you are surely aware, as a result of the recent election, recreational marijuana use has become legal in Nevada. Gordon Law has previously written of the challenges that employers had with medical marijuana (please see https://gordonlawlv.com/will-legal-pot-throw-you-into-a-kettle-of-litigation/#.WCSfIskQW6M). Recreational marijuana use may cause additional concerns for employers — this is particularly true if you suspect that one of your employees comes to work impaired.
As a preliminary matter, regardless if it is medical or recreational, it remains illegal to use marijuana in public. Thus, your staff cannot light up in the parking lot without committing a crime. Furthermore, it remains illegal to operate a vehicle while under the influence.
Without delving into whether your employee is committing a crime, you do need to consider how you are going to address the legalization of marijuana with your staff. The first place to look is if you have an existing drug policy — whether in an employee handbook or otherwise. If you do not have an existing policy, you should create one. An employee handbook is a natural place to have such a policy. Within the policy, you must clearly state what is expected of your employees and what actions you, as the employer, are prepared to take should those policies be violated.
The dichotomy of medical marijuana and recreational marijuana create extraordinary challenges for an employer. You are not permitted to delve into your employees’ medical conditions. Thus, if you suspect your employee of working while impaired, any investigation you contemplate may conflict with limitations under the Americans with Disabilities Act (ADA). Although the ADA is a federal law and marijuana remains illegal under federal law, an employee may still bring a claim against you for violation of the ADA if your action(s) can be shown to be discriminatory in relation to the underlying medical condition.
In all circumstances when it relates to employees, it is imperative that the employer manage expectations (preferably through written policies). Even more important is that if you have such policies, that you uniformly enforce them and that you document each step along the way.