Judicial systems have been used predominantly throughout the world to deal with disputes in various contexts, where criminal defendants, law enforcement and experts intervene daily to resolve deputies in a judicial manner (Silverman et al 2010). However, the characteristics of judicial systems differ from country/region to another, depending on the basis of the system which may impact the expert. To explain the above, it could be said that legal systems are divided into two systems, the adversarial system and the inquisitorial system. Conversely, a hybrid between these two systems formed another system identified as a mixed system. These derive from historical laws and judicial practices practiced over a considerable period of time, which have become improved and standardized over time. Debara.K in 2002 suggested that the basis for forming a jury was based on medieval modes of combat where two sides argue their points to crown a champion. Jonakait (2008) concluded that in the 18th century, legal systems developed into a phase where lawyers actively participated in English criminal trials, making the legal system more “adversarial.” Paradoxically, the inquisitorial system arose soon after the 13th century, as a result of mistrust in the adversarial system. Essentially, this system was formed by the French and then transferred horizontally to a few other countries which eventually became one of the two dominant legal systems in the world (Johnson.Het al 2008). In this short study, the English legal system will be elaborated in comparison to the Italian legal system. Before this, both the adversarial and inquisitorial systems will be discussed… halfway through the article… and Jones, M. (2008) History of criminal Justice, 4th ed. Waltham: Elsevier, p.67-70. Jonakait, R. (2008) The rise of the American adversary system: America before England, Widner Law review, 14(1), p.656. Koppen, J. and Penrod, S (2003) Adversarial justice versus inquisitorial justice: Psychological perspective on criminal justice systems, USA: Springer, p.29.Malleson, K. (2007) the legal system, New York: Oxford University press , p.11-14.Siegal, L. (2010) Criminology: The core, USA: Cengage learning, p.385-387.Silverman, J. and Silverman, S. (2010) How the justice system works, UK: A Discovery company, p.27.Smith, S. and Langan, B. (1992) Civil jury cases and verdict in large countries, Bureau of Justice statistics , - (1), p.3-10.Wall, W. (2010) Forensic science in the courts: the role of the expert witness, West Sussex: John Wiley and Sons, p.2-56.