Świadek koronny jako instytucja dowodowa oraz źródło informacji o przestępczości zorganizowanej

The author presents some practical aspects of the functioning of the immunity witness institution following the seven years of its existence in the Polish legal system. The paper contains an analysis of doctrinal as well as practical problems deriving directly from the utilisation of testimonies made by immunity witnesses. It is based on the results of research conducted using materials regarding the process of choosing candidates for immunity witnesses, as well as documents from criminal investigations and cases in courts where that institution was used. The author presents an analysis of police operational work during the process of choosing immunity witness candidates whose testimonies then shape the investigation as well as other evidence acquired during court hearings. It is compared with opinions expressed by judges, public prosecutors and police officers involved in the work with immunity witnesses at diffrrent stages of criminal procedure (e.g. receiving testimonies) and the immunity witness protection programme (e.g. physical protection of a witness). A consideration of these two aspects ensures a comprehensive diagnosis of that institution. There are two fundamental questions related to the subject matter: is the evidence effective in the Polish penal law? And is the evidence really necessary and useful in every respect?