From London's Metropolitan Police, apparently one of the first actual police forces, formed in 1829, (from Civitas, The Institute for the Study of Civil Society. These make a ton of sense to me.
The Nine Principles of Policing
1. To prevent crime and disorder, as an alternative to their repression by military force and severity of legal punishment.
2. To recognise always that the power of the police to fulfil their
functions and duties is dependent on public approval of their existence,
actions and behaviour and on their ability to secure and maintain
3. To recognise always that to secure and maintain the respect and
approval of the public means also the securing of the willing
co-operation of the public in the task of securing observance of laws.
4. To recognise always that the extent to which the co-operation of
the public can be secured diminishes proportionately the necessity of
the use of physical force and compulsion for achieving police
5. To seek and preserve public favour, not by pandering to public
opinion; but by constantly demonstrating absolutely impartial service to
law, in complete independence of policy, and without regard to the
justice or injustice of the substance of individual laws, by ready
offering of individual service and friendship to all members of the
public without regard to their wealth or social standing, by ready
exercise of courtesy and friendly good humour; and by ready offering of
individual sacrifice in protecting and preserving life.
6. To use physical force only when the exercise of persuasion, advice
and warning is found to be insufficient to obtain public co-operation
to an extent necessary to secure observance of law or to restore order,
and to use only the minimum degree of physical force which is necessary
on any particular occasion for achieving a police objective.
7. To maintain at all times a relationship with the public that gives
reality to the historic tradition that the police are the public and
that the public are the police, the police being only members of the
public who are paid to give full time attention to duties which are
incumbent on every citizen in the interests of community welfare and
8. To recognise always the need for strict adherence to
police-executive functions, and to refrain from even seeming to usurp
the powers of the judiciary of avenging individuals or the State, and of
authoritatively judging guilt and punishing the guilty.
9. To recognise always that the test of police efficiency is the
absence of crime and disorder, and not the visible evidence of police
action in dealing with them.