What sorts of policies exist to determine when the use of force is appropriate in policing and in corrections?
There is no one manuel for when and how law enforcement officers, including corrections officers, should use force. Each law enforcement agency or department trains its personnel according to its own departmental guidelines. And most major police and sheriff's departments have lawyers on staff who specializing in investigating the use of force by officers to ensure that use was consistent with departmental policy and with the law.
Having said that, there is a consensus among law enforcement agencies regarding the broad parameters for the use of force. The State of Illinois Law Enforcement Training and Standards Board, for example, published an "Evaluation of Guidelines for Use of Force Training," which notes,
"The Committee's charge was to establish uniform standards and guidelines that set forth curriculum and testing modes that address use of force alternatives which are reasonable, necessary and within social, moral, ethical and legal expectations...The Guidelines were developd in such a manner that they can be used as an overlay to determine if existing or proposed use of force models, training aids, and training programs meet the standards established by the Training Board."
According to the International Association of Chiefs of Police, the use of force is defined as "the amount of effort required by police to compel compliance by an unwilling subject." The levels of force, from the use of verbal commands all the way up to lethal use of firearms, are dictated entirely by the circumstances in which law enforcement officers find themselves. This goes also for corrections officers, who often work in a more stressful environment, especially those assigned to maximum or medium security prison facilities. Officers are trained to respond to all levels of threat, both to themselves and to innocent bystanders.
One or more instances of questionable uses of force within a department, city or state will typically involve a review of guidelines with the anticipation that changes will be made to address a pattern of misconduct or inappropriate uses of force. For example, in November 2011, Governor Jerry Brown of California, in response to such incidences on state university campuses, requested that state police review their "use of force" guidelines and make whatever changes were warranted.[see "Gov. Brown Requests Review of Police Use of Force Guidelines," The Daily Californian, November 28, 2011]
Basically, police officers are required to use their judgement in determining when and how to use force to subdue a suspect or save a life, including his or her own. Police academies spend considerable time training prospective officers, or cadets, in the proper procedures. Police officers are human, though, and no set of guidelines will prevent all misuses of force, especially where corrections officers are concerned. Working in a prison, where every inmate has been convicted of a crime, many for violent crimes including murder [exempting suspects held without bail who have not been tried yet, let alone convicted], poorly-paid, and sometimes under-trained prison guards are frequently threatened and even assaulted. For such individuals, knowing when to use force to prevent such an assault is nearly impossible given the environment in which they are working.