1. Introduction.
The work of a police officer is very important nowadays as people depend on police officers and detectives to protect their lives and property. A police officer performs responsible field enforcement duties involving the enforcement of all provisions of the Constitution. His duties are numerous and many-sided, he:
1) executes and serves all criminal processes resulting from enforcement activities;
2) ensures public safety and emergency functions;
3) holds an inquest of holders of permits and licenses issued by the department;
4) safeguards departmental equipment;
5) prepares reports of activities and offers programs on department activities to the public;
6) stays in contact with the general public.
Law enforcement officers carry out these duties in many ways that depend on the type and importance of their department. Besides, in many jurisdictions, one of their duties is also to exercise authority when it is obligatory.
The knowledge of the Constitution, of the Bill of Rights, and in particular, the knowledge of the rights of the accused are to be learned and practised during the work of a police officer.

2. Rights of the Accused.
Since the time of the American Revolution, the notion of the rights of the accused has changed. The 14th Amendment declaring the equal protection of the law meant the equal rights for citizens and for newly freed slaves. Later, this amendment has acquired another interpretation. Since 1960 the notion of equal protection has been expanded to other categories of people, thus illustrating the constitution's flexibility.
The rights are not designed to free the individual from community norms. They assist a responsible liberty, to make every one be free from arbitrary power. Any rights are the community's protection against the unwarranted interference in everyday life by the government (Urofsky, 1989, p.72). Rights set free the public and the individual at the same time.
Concerning the rights of the accused, the major notion of a due process is given in the Constitution.
The notion of the due process contains procedural and substantive rights. In other words, due process of law is what the Constitution has created to protect the wholeness of the criminal justice system. It denotes that every accused has the right to some processes to guarantee that he will be sent for a fair trial, carried out under the rules of the Constitution and in so that people can have firm belief that the system is working above board.
The United States is a nation built upon principles of liberty - principles that denote and prove a democratic form of government.
The Constitution was supposed to explain the rights, the duties and restrictions of the government. It was an important document in which the governmental duties and restrictions were so carefully defined. Although the government frequently violated the Constitution, the document fulfilled its function pretty well — making the USA the freest country in the world.
The constitutional provisions have passed the test of time having created the greatest democracy in the world and a governmental structure that is the most protective of individual freedom and liberty in history.
On the whole there are 27 amendments to the Constitution. The Bill of Rights gives the notion of the first ten amendments to the Constitution. We will examine those connected with the system of justice and the rights of people.
The fourth amendment states “the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized” (Bodenhamer, 1992, p.74). So, the fourth amendment guards against illegal arrests, searches and sequestrations of property.
The fifth amendment to the Constitution declares that “no person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury … nor shall any person be subject for the same offence to be twice put in jeopardy of life or limb; nor shall he be compelled in any criminal case to be a witness against himself, nor deprived of life, liberty, or property, without due process of law…“ (Levy, 1968, p.65). It must be clear that the fifth forbids trial for a major crime except after accusation by a grand jury. It forbids repeated trials for the same crime after a palliation and prohibits penalty without due process of law. Besides, it states that an accused person may not be forced to give evidence against himself.
The sixth amendment stresses that “in all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial by an impartial jury … and to be informed of the nature and cause of the accusation; to be confronted with the witness against him; to have compulsory process for obtaining Witnesses in his favor, and to have the Assistance of Counsel for his defense” (Bodenhamer, 1992, p.89). The sixth amendment demands trial by a jury and guarantees the right for legal lawyer for the accused.
The seventh amendment safeguards trial by jury in civil cases.
The eighth forbids unreasonable caution or penalty, as well as cruel punishment.
Besides, there is the fourteenth amendment to the USA constitution that describes equal protection of the law. That means that individuals, irrespective of their race, gender, or religion, must be treated as individuals without discrimination in accordance with his or her deserts before the law:
“Nor shall any State deprive any person of life, liberty, or property, without due process of law” (Bodenhamer, 1992, p.107).
The fourteenth amendment to the Constitution declares equal protection of the law. It requires equal protection of the laws for all people and it secures equal legal rights for people of color, women, and other groups.

4. Conclusion.
The paper briefly tells about the duties of a police officer in order to make clear all the importance of the work as people depend on a police officer because he protects the life of citizens as well as their property.
Besides, the knowledge of the law, the rights of people and of the accused is necessary for police officers.

References.
Anthony Lewis (1964) “Gideon's Trumpet”, New York: Random House.
David J. Bodenhamer (1992) “Fair Trial: Rights of the Accused in American History”, New York: Oxford University Press.
Leonard W. Levy (1968) “Origins of the Fifth Amendment”, New York: Oxford University Press.
Melvin I. Urofsky (1989) “The Continuity of Change: The Supreme Court and Individual Liberties”, Belmont, CA: Wadsworth Press.
Samuel Walker (1980) “Popular Justice: A History of American Criminal Justice”, New York: Oxford University Press.