Criminal psychology, also referred to as criminological psychology, is the study of the views, thoughts, intentions, actions and reactions of criminals and suspects. It is a subfield of criminology and applied psychology. Criminal psychologists have many roles within legal courts, including being called upon as expert witnesses and performing psychological assessments. Some types of psychiatry behaviour with aspects of criminal behaviour. Several definitions are used for criminal behaviour, including behaviour punishable by public law, behaviour considered immoral, behaviour violating social norms or traditions, or acts causing severe psychological harm. Criminal behaviour is often considered antisocial in nature. History Criminal psychology started the late 18th century. There were four key aspects of the development of criminal psychology: philosophical, medical, legal and biological. Before criminal psychology, there was a conflict in criminal law between medical experts and court judges on determining how to proceed with a majority of cases which specialized ated the development of a specialized sed field for individual investigations and assessments of suspects. It is generally accepted that criminal psychology was a predecessor to the broader field of criminology, which includes other fields such as criminal anthropology which studies more systemic aspects of crime as opposed to individual suspects and court cases. Profiling Criminal profiling, also known as offender profiling, is a form of criminal investigation, linking an offender's actions at the crime scene to their most likely characteristics. This is a practice that lies between the professions of criminology, forensic science and behavioural science. This is used in criminal psychology to help law enforcement and investigators narrow down and prioritize a pool of suspects. Part of a sub-field of forensic psychology called investigative psychology, criminal profiling has advanced substantially in methodology and grown in popularity since its conception in the late 1800s. However, there is a substantial lack of empirical research and effectiveness evaluations validating the practice of criminal profiling. Due to the lack of empirical research, it is important that criminal profiling is used as a tool in investigative cases. Cases should not depend on solely the profile but as well as traditional techniques as well. Criminal profiling is a process now known in the Federal Bureau of Investigation (FBI) as criminal investigative analysis. (see also: FBI method of profiling) Profilers, or criminal investigative analysts, are trained and experienced law enforcement officers who study every behavioural aspect and detail of an unsolved violent crime scene, in which