I dont know about Rikers but depending on the county or city jail, the local detentions centers can be worse than the state or federal correction facilities (ie prison) because of overall incompetence of local government. If you have a local government thats corrupt, incompetent, or just broke it can be hard to have a quality detention center. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.