Lindsay Clancy's murder trial begins with jury selection on Monday, July 20 — nearly three and a half years after the deaths of her three children in Duxbury, Massachusetts. Prosecutors just dropped the strangulation charges (July 9), narrowing the case to three counts of first-degree murder, and Clancy's defense has confirmed she'll argue lack of criminal responsibility — what's commonly called an insanity defense.But Massachusetts runs this defense backwards from almost every other state. Jon — an active 911 dispatcher with 11+ years of experience — breaks down what a call like Patrick Clancy's actually does to the person taking it, and why the 911 call itself may become one of the most important pieces of evidence at trial. Drew — a 29-year law enforcement veteran — walks through the legal mechanics: why the burden of proof in this case falls on the state, not the defense, and what that means for how this trial will actually be decided.