Criminal Justice is the system of practices and institutions of governments directed at upholding social control, deterring and mitigating crime, or sanctioning those who violate laws with criminal penalties and rehabilitation efforts. Those accused of crime have protections against abuse of investigatory and prosecution powers.

A criminal defense lawyer, also known as a defense attorney, is a lawyer specializing in the defense of individuals and companies charged with criminal conduct. Some criminal defense lawyers are privately retained, while others are employed by the various jurisdictions with criminal courts for appointment to represent indigent persons; the latter are generally called public defenders. The terminology is imprecise because each jurisdiction may have different practices with various levels of input from state and federal law or consent decrees. Some jurisdictions use a rotating system of appointments with judges appointing a private practice attorney or firm for each case.

Police are responsible for conducting criminal investigations. At the investigation stage, police gather and review information to figure out what happened. This may involve, for example, examining the place where the crime occurred and talking to victims and witnesses. Based on what they learn, the police decide whether there is enough evidence to prove an accused committed a crime. If they think there is, they may make a report to Crown counsel recommending that charges be laid.Like Crown counsel all police activities, including investigations, must be done independently.Here are the common steps in a police investigation.The investigation begins when a crime or an incident is reported or known to police.Police gather information from the victim, witnesses and other people involved.Police may ask the victim to complete a statement.Police may ask witnesses to complete a witness statement. In some situations, police may also examine the crime site to get any physical evidence. This may include forensic evidence.Police review the information collected and decide what action to take.

Prosecutors are Agents of the Attorney General and represent the interests of the general public in the criminal justice system. As a society, we share an interest in protecting ourselves from criminals and the damage they cause. Our law enforcement system investigates crime and prosecutes offenders. However, the justice system must also protect our valued rights and freedoms and convict only the guilty. The prosecutor’s job is to recognize these different and competing interests and conduct the prosecution's business in a way that best serves them all. Prosecutors also have a duty to act in a way that strikes a fair balance between the competing interests of convicting the guilty, protecting citizens’ rights and freedoms and protecting the public from criminals. As a result, prosecutors do not work simply to get convictions. They are not the representatives of any special interest group. They do not act as the lawyers for victims of crime. Prosecutors represent the interests of all of us in ensuring that prosecutions are conducted in a diligent, competent and fair way that respects the rights of all citizens.

he judge in an Irish courtroom usually sits on a raised platform at the top of the court and wears white collars, a black gown and wig. If there is no jury in a case, it is the judge who decides which party shall win and which party shall lose in a case. He or she listens to the evidence of both sides and to the submissions of the barristers (or solicitors). The judge may ask questions of any witness and of the barristers (or solicitors). The judge may give the judgment in the case at the end of the trial or he or she may "reserve" the judgment. When a judgment is reserved, the judge will take time to consider the case and then at some later stage deliver the judgment. If there is a jury in the case, it is the jury that decides the outcome of the case. The judge merely provides guidance to the jury and makes sure that the trial is run properly. The jury in a criminal trial has the very important function of deciding whether the person accused of the crime is guilty or not guilty. In April 2006 new rules were signed into effect changing the way judges in Ireland are addressed in court. In the past, judges in Ireland were referred to as "My Lord", or "His Lordship". Now, they will be addressed as "Judge" or referred to as "The Court". The only exception to this is in the case of the Chief Justice and President of the High Courts, who are addressed by their titles.

The term fair trial is a legal and ethical concept used to describe the procedural rules of a court and the treatment of those accused of a crime. According to democratic ideals, a fair trial is one in which the defendant's rights are respected throughout the trial, the trial is handled according to due process and established law, and the judgment is handed down by a neutral body. Ensuring a fair trial is what governs many of the standard procedural rules of courts in many regions, but the right to this treatment is by no means globally ensured. Many human rights groups seek to improve trial legislation throughout the world to increase the opportunity for justice worldwide. Sometimes the right to a fair trial is codified in declarations of rights; there is language about trial rights in the United States Constitution, the European Convention of Human Rights, and other national and international documents. The idea of this type of inherent and codified right is an ancient one; among other examples, it was part of the reason behind public legal debates in the ancient Roman forum. With the rise of monarchs and dictators who could pass judgment regardless of trial, it is easy to see how quickly this right could be dissolved if not codified and strictly followed on all levels of judgment.

A First Information Report (FIR) is a written document prepared by police organizations in Bangladesh, India, and Pakistan when they receive information about the commission of a cognizable offence. It is generally a complaint lodged with the police by the victim of a cognizable offense or by someone on his or her behalf, but anyone can make such a report either orally or in writing to the police.For a non cognizable offense a Community Service Register is created & registered.An FIR is an important document because it sets the process of criminal justice in motion. It is only after the FIR is registered in the police station that the police take up investigation of the case. Anyone who knows about the commission of a cognizable offence, including police officers, can file an FIR.As described in law,When information about the commission of a cognizable offence is given orally, the police must write it down.The person giving information or making a complaint has a right to demand that the information recorded by the police be read to him or her.Once the information has been recorded by the police, it must be signed by the person giving the information.