The system of criminal sanctions plays an important role in criminal investigation, making it possible for law enforcement officers to, for example, apprehend, arrest and commit a person for trial, or search premises and seize property. These measures or sanctions are based, in turn, on various fundamental concepts which express the standard of evidence which has to be met before the criminal sanctions can be executed. The majority of criminal sanctions may be applied only when there are reasonable grounds for suspicion. It is also only when the law enforcement officer is satisfied that there are reasonable grounds for suspicion that the person under suspicion acquires certain rights. In this case the law enforcement officer must inform the person under suspicion of the crime he/she is suspected of. He/she will then have the right to adequate legal representation and to keep himself/herself informed about the progress of the investigation, as well as request evidence to be collected and witnesses to be inquired, etc. It is at this point, i.e. when the reasonable suspicion standard has been met, that a prosecutor takes over the investigation.

Despite the crucial role of the standard of reasonable suspicion little research has been done on this issue, and there is hardly any legal literature or case law that has examined the real significance of this concept. This study therefore aims to bring clarity to the concept of reasonable suspicion by determining, in the first place, what it really means, and by subsequently formulating the requirements for typical cases in different crime categories that should be satisfied if the standard of evidence  ‘reasonable suspicion’ is to be met.