Relevancy of statements: statements to a summons admissible if maker unavailable or admission serves interest of justice. Section 136 makes statements signed upon appearance to a summons under section 70 admissible in prosecutions to prove their truth if the maker is dead, cannot be found, incapable of giving evidence, kept away by the adverse party, or if securing attendance would cause unreasonable delay or expense; alternatively, such a statement may be admitted when the maker is examined as a witness and the court, considering the circumstances, deems admission to be in the interest of justice.