One of the most important, fundamental rights enshrined by the Federal Constitution and the Missouri Constitution is the right of a defendant in a criminal proceeding to be confronted with the witnesses testifying against him/her (the “Confrontation Clause”). Specifically, the Sixth Amendment to the Federal Constitution provides in relevant part that In all criminal prosecutions, the accused shall enjoy the right […] to be confronted with the witnesses against him. The plain effect of this clause is that whenever you are being tried for a crime each and every single witness for the prosecution must actually be in the Court room to testify under oath so that you have an opportunity to conduct a cross-examination. Generally, witnesses cannot submit their testimony in writing (even if under oath or affirmation) and then have it offered into Court as a mere exhibit, nor can another witness generally provide hearsay testimony.
Why is the foregoing statement qualified with “generally” as opposed to “always”? It is because under Supreme Court precedent interpreting the Confrontation Clause the Court has found that where a witness is absent from trial, prior (1) testimonial statements are admissible only where the declarant is (2) unavailable and only where the defendant has had a (3) prior opportunity to cross-examine. A statement is non-testimonial if made in the course of police interrogation under circumstances objectively indicating that the primary purpose of the interrogation is to enable police assistance to meet an ongoing emergency. A state is testimonial when the circumstances objectively indicate that there is no such ongoing emergency and that the primary purpose of the interrogation is to establish or prove past events potentially relevant to later criminal prosecution.
As with all criminal cases, the procedure is often just as important as the substance because all evidence obtained in violation of established procedure is often suppressed and excluded from trial. The suppression of evidence, therefore, directly impacts whether a prosecution is able to prove a case beyond a reasonable doubt.