Constitution

• The U.S. Constitution, including the Bill of Rights, applies to all people. While the language in the Constitution is very broad and open to wide interpretation in its application, it's intended to apply to all people. There are some specific provisions regarding jurisprudence and punishments. The eighth Amendment, in particular, contains what is often thought of as the "no cruel and unusual punishment" clause.
  
  

State & Federal Law

• While there are federal and state laws specifically regarding prisons, those laws cannot, in theory, infringe upon any person's constitutional rights. So constitutional rights are generally the broadest rights for prisoners and the ultimate constraints for correctional officers.
  
  

Institutional Constraints

• Every prison has its own operating policies. Policies and procedures are generally developed by the governing jurisdiction: Federal prisons make theirs, states make theirs, municipalities make theirs and individual prisons may have autonomy to shape their own. The operating policies include specific constraints of correctional officers and policies that consider prisoners rights. The policies are usually developed with government legal counsel.
  
  Procedural constraints likely include such items as confiscating items from a prisoner; how to respond to a prisoner's request for medical treatment or medication; how to respond to an abusive, menacing or uncompliant prisoner; how to respond to prisoners' requests or demands for legal council; how to respond to suicide attempts; how to respond to prisoner-on-prisoner violence and sexual abuse; guidelines for cell extractions; and policies on solitary confinement.
  
  

Evolving Constraints

• Our system of jurisprudence relies on "precedence." Courts, in theory, do not adjudicate the same legal concept if another case with the same circumstances has been decided, unless there is some especially compelling reason to do so. Litigants often "test" laws by filing a lawsuit, asserting to courts that a law is illegal. Some laws are illegal and, in effect, get struck down from time to time. Other laws get redefined when litigation compels courts to change the law through a precedent-setting decision--usually made by the U.S. Supreme Court or other appellate court.