Crawford v Washington involved the admittance of a wife's statement to police against her husband at his trial for stabbing a man. The Supreme Court overruled prior precedent that allowed out-of-court statements if reliable, finding this violated the Confrontation Clause. Two later companion cases provided more guidance, finding a 911 call describing ongoing events was nontestimonial but a signed affidavit of past events was testimonial. However, the Court has still not provided a comprehensive definition of "testimonial" and what types of statements implicate the Confrontation Clause.