An expert is a person who possesses special expertise required by the court
during legal proceedings and is therefore commissioned to provide expert
analysis to clarify the actual circumstances of the case. As an objective assistant
to the court, the expert helps shape the course of criminal proceedings
and influences the final decision. Consequently, the expert plays a crucial role
in criminal proceedings. Unlike an ordinary witness, the expert’s work serves
as a direct cognitive source of evidence. Their expertise not only provides
knowledge of relevant facts but also assists the court in performing its judicial
function. An expert, unlike a witness, has an active role: they can suggest the
gathering of evidence, the provision of objects or data important for findings
and opinions; if he is present during the viewing, reconstruction of the event
or some other investigative act, he may suggest that individual circumstances
be clarified or propose questions for interrogation. A fair criminal procedure
is only possible if both the judge and the expert are impartial. The expert is
not an assistant to any party but rather an assistant to the court in uncovering
the truth. Experts are required to be not only knowledgeable but also objective
and impartial. The principle of impartiality and independence that applies to
the court also extends to experts. Therefore, any doubt on the impartiality of
the expert raises doubts about the impartiality of the court and simultaneously
threatens the equality of arms between the parties.
Key words: expert, expert opinion, criminal procedure, evidence, impartiality,
equality of arms, due process.