I suggest you contact your local bar association and request the name of an attorney who will take the case on as a tort action without charge to you. Do not discuss the case with anyone, especially on the internet.
For the record this has nothing to do with disability law. All police departments have what is called "The Patrol Guide", which is issued to officers and not generally available to the public. In every guide I know of, a prisoner who states they are diabetic and are having medical issues MUST be transported to the closest hospital or an EMS crew summoned. Immediately.