You do have a legal right to prohibit the keeping of firearms at your properties, just as you can prohibit tenants from keeping pets or parking oversize vehicles in your parking lots.
Your managers concerns are a bit off the mark: The United States Constitution (specifically, the Second Amendment, which concerns the peoples "right to bear arms") is aimed at the government, not at individuals like you. So, while recent Supreme Court decisions have struck down attempts to restrict gun ownership, these cases have all involved states or localities whose laws have been found to infringe on the amendment. You are neither a state nor a locality. You are simply a business owner who has wide latitude in deciding how your run the business.
Should you instigate such a policy at your properties more on how to do that below you should be prepared for another argument youre likely to hear. "Thats discrimination against gun owners!" will surely be lobbed your way. Again, nothing to fear, legally. Thats because gun owners are not a protected group under federal, state or local laws. Unlike members of a race, religion, ethnicity and so on, gun owners enjoy no protection from negative treatment aimed at them simply because they happen to own guns.
You certainly cant target protected groups with your policy, such as applying it to members of a particular race only, but you can refuse to rent to every applicant who wants to keep guns on the property. Now you must think about how to implement your new policy. For those tenants who have leases, youll have to wait until the leases are up to insert your new clause. You cant impose your new rule on tenants who are midlease, because doing so would entail a unilateral change in an important term or condition of the rental, which is exactly what a lease is intended to prohibit. But if you have month-to-month tenants, you can announce your new policy with proper notice, which is 30 days in most states. Tenants who are unhappy with the new rule will presumably refuse to sign your new lease or monthly agreement. If they dont move out voluntarily, theyll be candidates for eviction. - See more at:
http://www.inman.com/2013/02/14/woul....gtsXilbD.dpuf