Criminal Justice: Ex Post Facto Law ConceptName:Institutional affiliation:The Ex Post Facto Law ConceptCriminal justice is a broad, but important field that plays crucial role in the lives of the people. It is a practice that seeks to maintain the social order by discouraging and mitigating crime or punishing those who go against the law by imposing criminal penalties and rehabilitation efforts (Bottoms, & Tankebe, 2012, p. 119). Many countries have continuously strived to improve their laws on criminal justice to accommodate many other emerging issues. This paper will discuss the ex post facto law concept as well as statute of limitations and how they affect they law enforcement profession.Ex post facto law concept is the law concept that effectively transforms the legal status or the consequences of actions or doings that were committed or the overall relationships that were in existence before the enactment of the law (Duxbury, 2013, p. 135). In the criminal justice the concept may have adverse effects on the interpretation of the law. In most cases the ex post facto law may influence the interpretation of an action in a manner that seem to