Applicants and social groups

[LaDonna Davidson]

I currently have a tenant being evicted for none payment. This tenant is acquired and is clearly using illegal drugs. Now I have another mobile home for sale in the park. during my application vetting I noted that the applicant is friends with said tenant. At first thought "ok, maybe they could be acquaintances". Then as I drove through the park, applicant was at the tenants lot. While tenant is on house arrest. This indicates Pretty good friends. 

My question is can I legally deny his application for association? I have not received aback ground check yet. that is the last step if they make it that far.