The purpose of this dissertation is to empirically, analytically, and descriptively, investigate whether or not, and to what extent the fundamental human right to due process of Colombian Army members has been violated by national and international tribunals. The investigation is based on Human Rights and International Humanitarian Law (IHL), and analyses cases of Colombian Army members being tried for human rights and IHL abuses by Colombian and international courts. Thus, it argues that due to the “Fuero Militar” (Military Judiciary Jurisdiction) being weakened, the fundamental human right to due process has been violated for military personnel. Accordingly, the paper presents a hypothesis that suggests that political and legal changes of the Military Justice System in Colombia have resulted in due process violations to Colombian Army members. The paper provides analysis of: Firstly (a) the United Kingdom, The United States and the Colombian Armed Forces and Police, in terms of, chain of command, structure, Military Justice, rights and duties; (b) a detailed Colombian Army structure; (c) a comparison between the three countries, illustrating the reasons that made the Colombian context unique; (d) the due process from international legislation to Colombian legislation; (e) the Transitional Justice concept and its interference in the Colombian armed conflict. Secondly, the information collected in the 31 interviews with Colombian Army members being tried for human rights and IHL abuses; together with assessment of three high-profile cases in which Colombian Army members are being tried for human rights and IHL abuses: “Soacha”, “Mapiripan” and “Palacio de Justicia”. The analysis of the research findings concludes that the weakening of the “Fuero Militar” have increased the number of allegations of human rights violations in the particular case due process to servicemen. Finally, policy changes are suggested and the dissertation recommends that further research be conducted.