Amicus Curiae consists of a person or entity that is called or volunteers to intervene in a process in which it is not involved., with the objective of presenting its opinion on the matter debated in Court.
This is a Latin expression and literally means "friend of the court" or "friend of the court", in Portuguese. the plural of amicus curiae é amici curiae.
The purpose of amicus curiae it is to assist the Court, offering clarifications that may be essential to the resolution of the case. Its function is also characterized by calling the court's attention to facts that, until now, had not been noticed. The use of this procedural figure is justified by the need to support factual or legal theses in defense of public or private interests.
In this sense, the character of the amicus curiae it does not define itself in defending the legal interest of one of the parties, since it does not assume procedural powers. This figure is moved for a reason regardless of the parties involved in the process. That's why the amicus curiae is called "friend of the court" and not "friend of the parties".
According to new CPC (Code of Civil Procedure), chapter V, article 138, determines the conditions for the application of the amicus curiae in Brazil:
"Art. 138. The judge or the reporter, considering the relevance of the matter, the specificity of the subject object of the demand or the social repercussion of the controversy, may, by unappealable decision, ex officio or at the request of the parties or whoever intends to manifest, request or admit participation of a natural or legal person, agency or specialized entity, with adequate representation, within 15 (fifteen) days of its subpoena."
According to some authors, the emergence of the figure of amicus curiae would originate from medieval English criminal procedural law. At that time, the amicus curiae it presented only an informative role and, as a rule, they were impartial subjects and uninterested in the subject under debate.
However, there is some disagreement about this hypothesis. Other researchers point to the existence of a position similar to what is known today since ancient Roman law.