CHESTER – Kathryn “Kat” McDonough, one of the persons arrested in connection with Elizabeth “Lizzi” Marriott’s death, has pleaded guilty to all charges and agreed to work with prosecutors on their case against her former boyfriend Seth Mazzaglia.
On Thursday, July 25, McDonough pleaded to conspiracy, witness tampering and hindering prosecution in the strangling death of Marriott. According to police reports, McDonough lied to police and sought to mislead them during the search for Marriott in the days following her disappearance.
Marriott, 19, was living in Chester and commuting to the University of New Hampshire when last October, she failed to return to the home of her aunt and uncle with whom she was staying.
A missing person’s case soon turned into a murder investigation and both McDonough and Mazzaglia were implicated in her disappearance.
Both were indicted in April, Mazzaglia on two counts of first degree murder, one of second degree murder and one of Conspiracy to Commit Hindering Apprehension or Prosecution. One of the first degree murder charges indicates that Mazzaglia murdered Marriott before, after or while attempting to commit felonious sexual assault.
McDonough is looking at 1.5 to three years for her part in Marriott’s death. McDonough was sentenced to serve between 3.5 and 7 years on each charge, but most of that time was suspended. Chester police chief Bill Burke said the penalty for McDonough’s part in the death is too short, but conceded that it was a balancing act that the prosecution takes on in such cases.
The Chester police led the initial investigation, but it was soon taken over by state police and authorities on the seacoast. The department keeps in contact with Marriott’s family.
Marriott’s body has not been found.
Both Mazzaglia and McDonough are accused of deleting messages on their phones that discussed the planned visit and the disposing of Marriott’s body and possessions across the region. Authorities think that the two discussed how they would cover up the murder, creating a false alibi, or when that failed, how the death was accidental and took place during consensual sexual activity.
Marriott’s family released a poignant statement following McDonough’s plea deal. Her father, Bob Marriott, read the letter in the courtroom. It indicates an understanding of why the plea deal was reached and an acceptance of its terms, but goes on to state that “Kat’s moral responsibility for the actions surrounding Lizzi’s death make the maximum penalty of the charges too lenient, never mind the sentence that will be imposed.”
The letter goes on to speak of the cherished individual Marriott was and how deeply felt is her loss.
The letter concludes, “Katherine McDonough, someday, I hope that you can look back and face this tragedy and acknowledge to yourself your part in it. You had the chance to do the right thing, to try to help, to do something heroic. Your failure in that moment is why Lizzi isn’t here to live out her life.
“I wish I could have told Lizzi not to go to Kat’s house that night – she would still be alive and I wouldn’t be in this courtroom,” he wrote.