Sec. 3. FORM OF DEMAND. No demand for the extradition of a person charged with crime in another State shall be recognized by the Governor unless in writing, alleging, except in cases arising under Section 6, that the accused was present in the demanding State at the time of the commission of the alleged crime, and that thereafter he fled from the State, and accompanied by a copy of an indictment found or by information supported by affidavit in the State having jurisdiction of the crime, or by a copy of an affidavit before a magistrate there, together with a copy of any warrant which issued thereupon; or by a copy of a judgment of conviction or of a sentence imposed in execution thereof, together with a statement by the Executive Authority of the demanding State that the person claimed has escaped from confinement or has broken the terms of his bail, probation or parole. The indictment, information, or affidavit made before the magistrate must substantially charge the person demanded with having committed a crime under the law of that State; and the copy of indictment, information, affidavit, judgment of conviction or sentence must be authenticated by the Executive Authority making the demand; provided, however, that all such copies of the aforesaid instruments shall be in duplicate, one complete set of such instruments to be delivered to the defendant or to his attorney.