We first heard the name Lizzi Marriott when everyone else in New England did, on October 12, 2012. Her face was all over the news, framed in the kind of breathless graphics it seems TV stations always roll when a beautiful coed goes missing.
The following days brought long shots of divers emerging from cold black waters, tense TV press conferences delivered by tight-lipped officials, and heartbreaking vigils full of tears and candlelight. There was a poster that became a fixture on bulletin boards and shop counters all over the state, as if Lizzi might be discovered wandering Concord’s downtown or hiking in the White Mountains, the victim of some kind of innocent miscommunication.
As we followed the coverage and saw those posters multiply, we suspected Lizzi had been the victim of something far worse. Everyone else in New England did too.
As true crime authors, we’re often asked how we decide which cases to write about. The truth is that, while every murder is worth exploring on behalf of the victim, rare is the case that can fill the pages of a book, because in most, there is no before and there is no after; there is only the act itself and whatever punishment comes after it. But in the months following Lizzi Marriott’s disappearance, it became clear that Seth Mazzaglia’s arrest, followed by Kat McDonough’s, pointed to a far more confounding narrative than the one law enforcement officials had laid out in the early days of the investigation.
It’s not hard to fall in love with Lizzi Marriott and her family. Her father, Bob Marriott, maintains a Facebook page where he posts photos that reveal what a dazzling young woman she was. It seems no image of Lizzi exists in which she’s not smiling, performing, or rescuing some wild creature in peril. Everyone who followed this case felt the Marriotts’ loss very deeply. It was impossible not to. We corresponded with Bob Marriott for several months while working on this project, and it’s clear that his pain hasn’t diminished with the passage of time, and that he will never know why his daughter was taken away from those who loved her.
If there’s one answer we do have to that impossible question, it’s the one the jury handed down. Lizzi wasn’t a victim because of her extraordinary openness and humanity or because she was “too trusting.” She was a victim because Seth Mazzaglia orchestrated the events that ended her life.
We could not have anticipated the overwhelming complexity of Seth’s fantasy world before we began researching this case. His story—that of an emotionally stunted loner whose adolescent notions about sex and power evolved into a longtime pattern of sexual violence—wasn’t of particular interest to us. From the outset, it was clear that this would not be a book about Seth Mazzaglia, and although we knew his dark inner life would take up pages, it was never our central focus.
For us, it was Kat McDonough who emerged as the central and most confounding figure in this case. We may never know the full measure of her guilt or innocence, but we do know she wasn’t the first woman Seth abused and pulled into his rage-fueled fantasies. And if not for Lizzi’s murder and his conviction for it, Kat would probably not have been the last.
By all accounts, Kat was a typical seventeen-year-old when she met Seth. She attended high school, hung out with her friends, performed in plays, and—perhaps most typical of all—had a drama-filled relationship with her father.
But in the very short time she was with Seth, Kat evolved into a person who knowingly, perhaps willingly, pushed the defiled body of a friend into a tidal river in order to conceal a rape and murder. The questions around how that evolution happened were the ones we sought to answer. How did Kat’s course change so radically in such a short period of time? Was she fully under the influence of an abuser? Or would digging into her story reveal a darkness that had been inside her all along?
As we attempted to unravel the complex investigation and legal maneuvers that came to define the public’s perception of this case, we sometimes found ourselves investigating in circles or digging out of rabbit warrens that began with simple fact-checking phone calls. Much of this work helped us get closer to answering questions that continue to surround the guilty, but it also served to reveal something larger: While the truth is somewhat easy to prove, lies are nearly impossible to verify, and the gray area between the two is the most difficult to navigate of all.
Bob and Melissa Marriott ultimately chose not to contribute to this book. Although they were eager to share Lizzi’s story before trial, the family has been disappointed with certain characterizations of Lizzi in the media and with depictions of the events surrounding her murder. We respected their decision and relied instead on information from previous interviews, Lizzi’s own writings, and the public record in order to flesh out some details.
During our final correspondence, Bob did make two requests on behalf of his family. First, he wanted to raise awareness of the scholarship set up in Lizzi’s name. He also asked, “Are you addressing domestic abuse at all? One thing that can come out of this is education about the cycle of abuse.”
We believe this issue is a central theme in this story, and we hope that readers come to know more about that cycle as they read this book.
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At the time of this book’s publication, Seth Mazzaglia’s conviction is under appeal at the New Hampshire Supreme Court. Should the court vacate the verdict and order a new trial, he will be presumed innocent until a new jury weighs in on the crime.
There’s one aspect of Seth’s case that is no longer an open question. In 2015, New Hampshire Governor Maggie Hassan signed House Bill 225 into law. The bill, which had rare bipartisan support as it sailed through the state’s House and Senate, makes it mandatory for defendants to appear in person during victim impact statements. It was drafted in direct response to Seth Mazzaglia’s attempt to skip his own sentencing and his desire to avoid listening to Lizzi Marriott’s family “yell and whine and bitch and moan and scream” about her murder.