Criminal justice systems worldwide are remarkably diverse, reflecting the many cultural, historical, and socioeconomic circumstances in which they have evolved. Despite their variations, many of these systems have parallels, particularly regarding cultural norms, societal ideals, and legal traditions. The cornerstone of every criminal justice system is intricately connected with the legislative framework of the nation where it functions, which serves as the base of its structure, methods, and values.

Around the world, legal systems can be broadly categorised into four primary types, each of which influences the functioning of the criminal justice system within that particular jurisdiction. These legal systems have developed over centuries and are shaped by historical events, philosophical ideas, religious beliefs, and the interactions between different societies. Consequently, the criminal justice systems derived from these legal frameworks are as varied as the nations and cultures implementing them. Yet, they often exhibit similar features when there is a shared cultural or societal heritage.

Common Law

Common law systems are precedent-based, meaning judges make decisions based on previous court opinions. Examples include the U.S., Canada, and the United Kingdom. Common law relies heavily on stare-decisis, a Latin term meaning "to stand by things decided." This principle dictates that judges follow the legal reasoning and rulings set in previous decisions(precedents) when dealing with similar cases. Precedents established by higher courts apply to lesser courts within the same jurisdiction. This provides uniformity and predictability in the way criminal matters are resolved.

The content of criminal law is primarily consistent among common-law jurisdictions. In both the United Kingdom and the United States, the twentieth century was seen as a time when strict law enforcement might remove bad conduct. In the early twentieth century, this resulted in the criminalization of much personal behavior—including some sexual practices, gambling, and the use of alcohol and drugs—that had previously been beyond the reach of the law, with the prohibition of alcoholic beverages in the United States lasting from 1919 to 1933. At the turn of the twenty-first century, several of these acts were addressed as medical or psychiatric issues rather than criminal ones.

Civil Law

Civil law systems, often known as continental or Romano-Germanic, exist on all continents and account for around 60% of global territory. They are based on concepts, classifications, and principles originating from Roman law, with some influence from canon law, and are sometimes significantly augmented or modified by local custom or culture. The civil law tradition, although secularised over centuries and emphasising individual freedom, encourages human collaboration.

The civil law system is wherein the legal system of countries prioritise codified statutes, meaning the law is meticulously written down in comprehensive codes. Judges in civil law systems primarily act as interpreters of the existing laws, and the previous court decisions hold lesser value as binding precedents of common law. The focus on codified law creates a more structured and centralised system.

In its technical, restrictive definition, civil law refers to the law governing individuals, objects, and their interactions, omitting not just criminal law but also commercial law, labour law, and so on. Codification occurred in most civil law nations, with the French Civil Code and the German BGB being the most influential.

Religious Legal System

Religious traditions frequently include ethical and moral standards to instruct adherents. However, the significance of these rules in a religion's overarching belief system differs substantially. Some faiths, such as Judaism, Islam, and the Baha'i Faith, emphasize the importance of divinely revealed rules that control individual and societal behavior. In contrast, other religions, such as Christianity, tend to downplay the importance of a codified legal system. They value timeless moral principles over specific civil or legal laws, which may be less important. This expresses religious ideas such as "grace over law.

According to Juriglobe,36 countries have a religious or mixed religious legal system, whereas 41 have customary systems of law that may incorporate religious aspects. Religious legal systems are founded on the religious group's holy texts and traditions and provide direction for satisfying spiritual and temporal commitments. The state may embrace this religious law in its entirety or part as state law and practice, or it may allow a minority group to employ religious law to administer communal affairs in addition to secular laws.

It is crucial to highlight that the implementation of religious legal systems varies. In certain nations, they serve as the foundation for national legal codes. In others, they may control personal concerns inside religious groups or coexist with secular law. Religious legal systems provide a unique perspective on the law, emphasising morality, tradition, and divine direction.

Study on Adversarial & Inquisitorial System of Justice

Adversarial System
The adversarial system is often associated with common law countries like the US or the UK. The system operates under the principle that the truth emerges most effectively through a fair contest between the two parties involved in the case. Prosecutors represent the state, i.e., the victims, and the defense attorneys represent the accused. The judge acts as a neutral referee in the clash in courts between the two parties, each presenting their strongest arguments and evidence.

The judge ensures that fairness and rules of evidence are upheld in determining the guilt or innocence of the parties involved. This method imposes a significant burden on both prosecution and defence. Prosecutors must compile compelling evidence to persuade jurors of the defendant's guilt beyond a reasonable doubt. Meanwhile, defence attorneys work to identify flaws in the prosecution's evidence, create reasonable doubt, or advocate for mercy in sentences. The jury, made up of regular persons, is responsible for analysing the evidence and finding guilt or innocence.

Benefits of Adevrsaial System
In emphasising the presumption of innocence, the adversarial system ensures rigorous safeguards for the accused. The defense attorneys are guaranteed that they have access to evidence, the right to cross examination of witnesses and the accused, and the accused has the privilege against self-incrimination.

The adversarial system values skillful legal representation, as lawyers play a crucial role in ensuring fair trials and protecting individual rights.

The open court proceedings in the system allow the public to observe the justice system in action, fostering accountability and trust.

Cons of Adversarial System
The adversarial system emphasizes on winning, which can, at times, overshadow the pursuit of truth. Skilled lawyers can use loopholes and technicalities to create doubts in the jury and the judge rather than focusing on presenting all relevant information.

Adervarsial trials can be expensive and time-consuming, requiring extensive resources for both the defence and the prosecution. This, in turn, disadvantages law-income defendants who may not have the best legal representation.

Juries of laypeople may struggle with complicated legal arguments or misread evidence, perhaps leading to miscarriages of justice.

Inquisitorial System
Inquisitorial systems, common in civil law nations such as France and Germany, employ a more collaborative approach to determining the truth. The judge takes a more active role, presiding over the inquiry and trial. The judge can examine witnesses directly, acquire evidence, and even establish lines of inquiry that neither side has offered. The emphasis is less on combative competition and more on a collaborative effort to discover all pertinent information. In contrast to adversarial systems, inquisitorial systems have pre-trial sessions presided over by a judge.

This judge leads the investigation into the case, looking for material that might help or hurt the prosecution or defence. Witnesses are invited to testify, and the accused is entitled to legal representation but is not required to speak. Their evidence, if provided, is not under oath.

Variations exist within inquisitorial systems. In Germany, prosecutors and judges work together to conduct investigations. France, meanwhile, takes a different strategy. Prosecutors make their recommendations only when the inquiry is concluded. In both nations, the investigating judge is an important figure. They will only propose a trial if they believe there is adequate evidence to support the accused's guilt. Inquisitorial processes can be speedier and less expensive than adversarial trials since they focus on evidence collection rather than courtroom confrontations.

Benefits of Inquisitorial System
The active role of the judges promotes a more thorough investigation, which leads to a more nuanced understanding of the facts and compensates for potential shortcomings in legal interpretations.

The lesser reliance on attorneys helps the system overcome any downsides that may lead to miscarriage of justice due to unfair or inadequate legal representation.

Inquisitorial processes can be speedier and less expensive than adversarial trials since they focus on evidence collection rather than courtroom confrontations.

Cons of Inquisitorial System
As the judge as an individual plays an active role, it raises concerns about the impartiality that can occur due to human bias. A judge who becomes convinced of the guilt early in the trial may be less likely to consider evidence contradicting the view. This phenomenon is known as Confirmation bias.

The focus on investigative efficiency can sometimes come at the cost of the rights of the accused. Defendants have less control over the direction of the investigation, and their rights against self-incrimination can be violated significantly.

These types of trials are often closed-door investigations that limit public scrutiny, thereby not ensuring the accountability and trust factors between the different stakeholders of the criminal justice system.

The decision between adversarial and inquisitorial systems indicates a fundamental philosophical distinction. The adversarial system prioritises individual rights and the protection of the innocent, even if it means inefficiency. The inquisitorial system prioritises truth and efficiency in investigations, even if it gives the state additional authority.

In conclusion, it is important to recognize that there is no universally superior legal system between the adversarial and inquisitorial traditions. Each system brings its own set of strengths and limitations to the table. The adversarial system, emphasizing the contest between opposing parties, fosters a competitive environment that can lead to thorough examination and vigorous defense. On the other hand, the inquisitorial system, focusing on a proactive judicial role in investigating cases, aims to ensure a more comprehensive search for truth and reduce the risk of oversight.

Given these distinct advantages, the most effective approach may be integrating elements from both systems to create a hybrid model. Such a system could leverage the adversarial tradition's rigorous defense and cross-examination procedures while incorporating the inquisitorial tradition's proactive investigative measures. By combining these strengths, a hybrid system could potentially offer a more balanced and fair judicial process, addressing the weaknesses inherent in each system and striving towards a more equitable pursuit of justice.