Guilty until proven innocent?

[KWG1956]

My 16 yr old son was arrested in June/2008 for 3rd degree burglary/petit larceny, because of this I now have custody of him. He has moved in with me and his 25 yr old brother. The lease is in the 25 yr olds name. In July I put a $100.00 deposit down on a 3BR apartment , scheduled to move in Sept 1st. My oldest son recently received a phone call from the rental office stating that we might not be able to have the 3BR apartment because they read in the local newspaper that his 16 yr old brother had been arrested in June/2008. They told him that his brother had to move out immediately, that they had the right to protect the rights and safety of the other tenants in the apartment complex from him possibly commiting crimes against them. He has not been convicted of any crime only arrested. My question is what legal ground do they have for making such a request.