S8, E8: One Dominance From Murder

In October 2012, a 19 year old sophomore named Lizzi Marriott just started at University of New Hampshire. She was studying marine biology and living with her aunt and uncle Tony and Becki Hanna. On Tuesday October 9th, Lissi said she was going to a friend's house and would be home no later than 12, 12:30. But the by next morning, Lizzi had not come back. The aunt and uncle tried to brush it off, remembering Lizzi was 19. But by the next morning, she still hadn’t returned. At this point, they decided they had to let Lizzi's parents know. They lived a couple hours away in Massachusetts. The Bob and Melissa Mariott immediately called police to report their daughter missing. Friends informed police who Lizzi was supposed to see that night, Kat McDonough. Lizzi and Kat had met working at the local Target. Nate McNeal, who also worked at the Target knew Kat McDonough well, as she and his sister had been friends since kindergarten. Nate even texted Kat and asked: 'Hey, did Lizzi ever come over to your house? No one seems to know where she is.' And Kat texted back, 'No. I didn't see her. She never came over.' Kat was well known in the community as a normal teenager. She was into the local theater scene and that’s where in 2011 she met Seth Mazzaglia. But once they started dating, Kat changed. As soon as she turned 18, Kat moved in with Seth – who was 29 – almost 10 years older than her. Her family didn’t approve of the relationship so she cut ties with them. Seth worked at a local electronics store, taught martial arts, and was a trained EMT. When investigators started looking into him, his name kept popping up on sex and bondage sites. They also discovered that Kat had posted some dark pictures of herself online using screen names like "Vampirate Actress" and "Miss Scarlett." And Kat and Seth had been advertising on fetish websites for a third person into their relationship. Three days after Lizzi's went missing, police brought Kat McDonough and Seth Mazzaglia in for questioning – at the same time but in separate rooms. Kat stuck to her story that Lizzi never showed that night. After about two hours she stopped answering any questions. Police told her she was free to go, but she stayed and waited for Seth. In another room, Seth was telling police totally different story. He said Lizzi Marriott was at their apartment. He said there was sex involved, then something went wrong and Lizzi died. His interview lasted 11 hours. Seth told them that after Lizzi died, he panicked and brought her body to Peirce Island, which is an area where the Piscataqua River meets the Atlantic Ocean. The rest of his interrogation was sealed, so we don’t have any more info on what else he told police then. He was arrested and charged with the murder of Lizzi Marriott. Police immediately started searching Pierce Island but found nothing. They searched the Piscataqua River for weeks but never found Lizzi’s body. In the dumpster behind Kat and Seth’s apartment they recovered a trash bag containing men's underwear, a pair of black gloves and Lizzi's sweatshirt. Two days after Seth was arrested, Kat met with Seth’s lawyers hoping to clear his name. She goes back to police and is videotaped as they review her original statement. This time she admits that Lizzi did come over that night but her death was an accident. Kat said the night started with the three of them watching a movie and playing cards, which then led to consensual group sex – as it often does. Kat said Lizzi agreed to be tied up with bondage ropes and Kat draws a sketch of the harness. Then she stood and demonstrated how she was positioned over Lizzi. And then she tells them that Lizzi had a seizure, suffocated and died as she was lying under her on the floor. 2 months later Kat was arrested, but not for murder. She was charged with three counts involving hindering an investigation and ordered to have no further contact with Seth. Because they hadn’t found Lizzi’s body, prosecutors needed Kat to testimony against Seth, so they offered her a deal. Instead of a possible 21-year sentence, she'd get a maximum of 3 years for her testimony. So she took it. It took 2 years for Seth to go on trial. During that time a few other pieces of information was revealed. Nate McNeal said Lizzi had a girlfriend named Brittany and they were in a long-term, committed relationship. So he doesn’t believe that Lizzi would have gone to Kat and Seth’s apartment and participated in any consensual sexual activity. Then there is a girl named Catherine who dated Seth when she was in high school and he was in college in upstate New York. She fully believed that Lizzi’s death was premeditated based on her experiences with him. According to Catherine, Seth has always been into BDSM and he became increasingly violent and sexually abusive as their relationship went on. And he gradually took control over her entire life. In 2002 they moved to New Hampshire together, and Seth started trying to bring other women into their relationship. Catherine didn’t leave because she truly thought he would hunt her down and kill her if she did. She was 600 miles away from her friends and family. But eventually she got the courage to try and went into hiding. So in May 2014, Seth’s trial began. And Kat, the prosecution’s star witness, tells yet another version of what happened that night. Now she testifies that she witnessed Seth murder Lizzi. She tells the jury that they engage in domination and that Seth is the master and she is the submissive. The prosecution read a text message Seth sent to Kat 6 weeks before Lizzi's death: "'It's time I punished you, you filthy little whore. You choose a friend, any of yours will do ... and you offer her to me that I may do anything I wish with her, while you watch.'" Kat testifies that she invited Lizzi over that night for this reason. Lizzi arrived at their apartment at around 8:50pm. They picked out a movie and Kat suggested they play strip poker. Once Kat was naked and Lizzi was down to her underwear, Seth suggested that Kat and Lizzi kiss. But Lizzi said she wasn’t comfortable with that because she was in a committed relationship. So then Seth asked if he and Kat could have sex while Lizzi was in the room. But she wasn’t cool with that either. Seth, the dominator, does not being to be told no. Kat and Lizzi sat on the floor watching a movie, and Seth was sitting behind them on a futon. He quietly put on gloves, grabbed a rope and put it around Lizzi’s head. According to Kat, Lizzi let out a quick noise and then stopped moving. And then Seth raped Lizzi. Kat then identified the gloves the police took from the dumpster as the ones Seth wore. She testified that she did nothing to help Lizzi, stop Seth or call for help. Next Roberta Gerkin, a friend of Seth’s, testified. Roberta said she got a strange call from Kat around 10:50 pm that night. They wanted her to come over right away. Roberta, and her boyfriend, Paul Hickok, arrived a little after 11 p.m. and the first thing they see is the body of a girl on the floor. Seth was sitting near the girl’s head, kinda rocking back and forth saying “I went too far. I went too far.” And Kat was in the fetal position in the kitchen. Roberta and Paul wanted nothing to do with the situation. They suggested that Kat and Seth call 911 and left. They didn’t call 911 themselves. Next Kat and Seth wrapped Lizzi’s body in a tarp and then put her into a suitcase. They put her body in Lizzi’s car and took backroads out to Pierce Island. Kat testified that Seth took Lizzi’s body out of the suitcase and pushed it over a cliff. Except it was low tide and she landed on rocks below. Seth ordered Kat to climb the 35 feet down, cover her in seaweed, and drag her body into the water. The spend the rest of the night getting rid of the evidence: the suitcase, Lizzi's clothing, and the rope. None of it has been found. And they parked Lizzi's car in a lot at the University of New Hampshire and 6 miles back to their apartment. Seth’s defense attorney tried to paint Kat as the murderer and Seth as the accomplice. It took the jury a day and a half to find Seth Mazzaglia guilty of first degree murder by strangulation, first-degree rape and murder, and 2 counts of conspiracy. At his sentencing Seth addressed the court and said, "I did not rape and murder Elizabeth Marriott. I did play a part in covering up her death. ...and for that I am truly sorry." The judge sentenced him to life without parole. Kat was released in 2016 after serving her 3-year sentence. That same year Seth filed an appeal arguing that that statements Lizzi allegedly made to friends about sex should have been admissible as part of his defense. But there is a rape shield law in New Hampshire that prohibits an accuser's prior “sexual activity" from being introduced as evidence of consent by a defendant. GOOD FOR NH! The court denied his appeal. Lizzi’s body has never been found. Sources: CBS news .com The 48 hours episode Dangerous Games: the Death of Lizzie Marriott from 2015 Boston Herald .com