Conflict of interest with tenant/guest of tenant

[Angela Brown]

My fiance works for the department of corrections and must report any conflicts of interest with his job.  We just recently purchased our first rental and are unsure how to include this conflict of interest clause in the lease.  While we can ask if the tenant has a criminal history before we rent to them, how would we appropriately handle a guest of the tenant that has a criminal history, but is not on the lease?  We want to include some type of verbiage in the lease, in addition to telling perspective applicants, but are unsure how to do this without breaking any laws.   We basically want to advise them 'if there is anyone on the property at any time that poses a direct conflict of interest with the owners of the property, we the owners reserve the right to ask you to leave'  would this verbiage work?  Has anyone else encounted a similar scenario?  If so, how did you handle it?  Any thoughts or insight is greatly appreciated!