I find that to be somewhat of a touchy situation from my viewpoint as a background screener, given the fact that “technically” they are not included in the lease and therefore not subject to certain disqualifiers.
Does your association have any written policies or by-laws that defines outside guests?
For instance, we provide our background screening services to multiple charities that allow family members to come in and out of the premises where a sick family member is being treated, even if they are not staying overnight, but are by definition in the premises a vast majority of the time.
In addition, have there been any complaints from any other tenants in your park? if so, that may be probable cause for the police to intervene and maybe enough to let that person know they are under their radar.