Woman in sex offering, death case released from prison

CONCORD, N.H. -- A New Hampshire woman is free after serving a three-year prison sentence for luring a co-worker to her apartment in 2012 as a sex offering to her domineering boyfriend, then helping him dispose of the co-worker's body after authorities said he strangled and raped the woman.

Kathryn "Kat" McDonough was released from the women's prison in Goffstown at 12:05 a.m. Saturday, said corrections spokesman Jeff Lyons.

The 22-year-old pleaded guilty in 2013 to lying about the disappearance and death of 19-year-old Elizabeth "Lizzi" Marriott, of Westborough, Massachusetts. She testified against Seth Mazzaglia, describing their sexual relationship marked by bondage and sadomasochism. He was convicted of murder, and is serving a sentence of life without parole.

Marriott was killed weeks after beginning her sophomore year as a marine biology major at the University of New Hampshire in Durham. She had worked with McDonough at a department store. Her body has not been recovered.

McDonough first told investigators Marriott died during rough sex between them using restraints. After getting immunity from prosecution, she changed her story, saying Mazzaglia killed Marriott after she rejected him.

"You had the chance to do the right thing -- to try to help, to do something heroic," Marriott's father, Bob Marriott, said at McDonough's sentencing. "Your failure in that moment is why Lizzi is not here to live out her life."

McDonough testified Mazzaglia demanded McDonough find him a sex partner. She said Marriott went to McDonough and Mazzaglia's home in Dover, thinking she was going to watch a movie or play a video game. Instead, McDonough testified, Mazzaglia strangled the woman with a rope.

McDonough and Mazzaglia said they used Marriott's car to transport her body and dumped it off of Portsmouth's Peirce island.

McDonough was on the stand for 10 days. She testified Mazzaglia, now 33, was angry at her when she left him for nearly two weeks as she attended theater camp and demanded she bring him another woman to join in their sexual escapades.

Mazzaglia's lawyers said McDonough was the dominatrix, a woman who made Mazzaglia her sex slave and was obsessed with finding another woman to dominate. They said she lied and testified against him to get a more lenient sentence. McDonough testified she was the submissive in their relationship.

During cross-examination, McDonough began sobbing as she blurted out she couldn't remember minor details from the night Marriott was killed. She said the image of Mazzaglia strangling Marriott took over her mind. When the witness wasn't visibly tearing up, defense attorney Joachim Barth challenged her outburst, asking "You cry without tears, Ms. McDonough?" She did not reply.

Parole was denied for McDonough in November 2014. The board said McDonough could apply again once she takes mental health classes and develops a better post-release plan that involves her living out-of-state. Chairwoman Donna Sytek said, "You got the deal of the century." McDonough told the board she'd had a lot of time to think about "what a horrible, horrible thing it was. I allowed someone's life to end."

As her release from prison neared, she planned to live with her father on the seacoast. The parole board was concerned that she not live so close to the scene of the crimes. Because of her notoriety, board members said, McDonough would have difficulty finding a job or even being in public near where the crime occurred. But with the sentence served, she is under no obligation to follow the board's guidelines, and the board can't impose any conditions on her. She doesn't have to tell authorities where she will live.

McDonough declined an interview request from The Associated Press, and her attorney did not respond to a message seeking comment.