The actions of proof in criminal proceedings in particular takes place and the expertise of its specificity. The role, tasks and responsibilities expert is essentially did not change regardless of the current reform of criminal legislation, which continues to present the same problems that existed even before the initiation of changes in criminal procedural law in the past ten years. Answers to questions on the orders of the court shall give the expert are oft en not simple, nor can they give an answer immediately. Providing expert findings, conclusions and opinions of the whole depends on many factors, previous actions, and even other, pre-expertise. The legal nature of expertise, duties and rights expert, control expertise, awards and fees for the expertise, the role of expert consultants and other specifics of these actions speaks to prove this article.