How do I deny an annoying rental applicant?

[Bonnie Freeman]

I manage a small apartment community (35 units) in a highly sought after part of town. Our rental agreements are now month-to-month, which has given tenants the flexibility to move in the event of a job loss or illness during the pandemic, and by the same token, the owner can issue a 30-day notice of non-renewal to get rid of problem tenants without having to go through a lengthy eviction process. We are fortunate that most of our tenants have lived here for more than 5 years, and whenever a unit does go on the market, it usually takes a week, two at the most, before it is rented. The problem is, we are in the process of getting rid of a tenant who was a problem from the outset. She complains about everything, has a very obnoxious attitude, and has been just plain miserable to deal with. We currently have four units that will be available next month, and applications are starting to come in. There is one applicant who is excellent on paper. She meets all the criteria however; it has become abundantly clear that she is going to be another PITA. She called me five times in one day and left multiple voicemails. Today she did a walkthrough and was very nitpicky even though she knows the unit is not 100 percent ready for move in. As she was leaving I asked her to text me when she was ready to drop off her application, so I could meet her in a designated location as I do not not like applicants to know where in the complex I live until they have been approved to move in. Instead of following instructions, she asked one of the tenants in the complex where I live, and she left the application under my doormat. These are just a few examples of how pushy and she has been. The owner does not want a repeat of the nightmare we are currently dealing with. How do we deny her application without running the risk of creating a legal problem for ourselves?