This law on police powers in contained in the Police and criminal Evidence Act of 1984.There are 8 codes of practice under which the police can do all the investigation these include stop and search ,detention and questioning ,identification interviewing ,power of arrest,visual recording .
It is believed that the rights of a citizen suspected of a criminal offence are protected under these codes of practice contained under Criminal Evidence Act of 1984, because the parliament believes that apart from criminal investigations it is necessary to keep a balance by protecting the rights of people and preventing them from being unnecessarily detained,the parliament has tried to solve this problem by introducing the above mentioned codes of practice and also under those codes providing limitations for arrest to prevent the suspect from causing physical injury to himself or other person or to prevent a person suffereing from an injury or commiting an offence against public decency.
There are also limits for detention where the suspect is kept under custody for 24 hours after which the person should charge or release the person who has been arrested on a suspicion of commiting a crime, the police may keep the person for another 12 hours if they have the permission of the senior officer ,to detain a person for more than 36 hrs the police must apply to the magistrates court.
The main power the citizens hold under the police and criminal evidence act 1984 is the citizens right to complain against the police, this is the weapon for the citizens who believe that the police have exceeded their powers and can complain againts those to the police authorities.The type of complaint then determines how it is to be dealt with , if they are minor complaints they are dealt informally and if proved the individual who filed the complain receives an apology and that is the end of the matter ,whereas if it is a major complaint then it is investigated by the police force and necessary actions are taken against the police officer.
In this way we can say that the rights of the citizens are highly protected under the police and criminal evidence act of 1984 and the parliament maintains the balance of protecting the liberty of the public and the police to continue there investigation in a easy -going manner under the bondaries of the codes of practice.