The trial court permitted the adult alleged victim in a sexual assault case to testify from behind a one-way glass screen which prevented her from seeing the defendant but permitted the defendant and the jury to see her demeanor. The court permitted its use after one day of testimony during which the witness hyperventilated, cried, sobbed, and sometimes made keening noises while testifying. The witness had apparently been treated by paramedics during the preliminary hearing. The appellate court held that the trial courts action violated the constitutional right to confrontation without holding an evidentiary hearing to determine whether, and to what degree, the witness anxiety was due to the defendants presence, rather than general emotional fragility. The trial court was required to make a case specific finding of necessity before dispensing with a face to face confrontation with an adult witness.