Crime & Safety

Witness to Lizzi Marriott Murder: 'I Did Lie For Him'

Kat McDonough stepped down from the stand but not before the defense assailed her credibility one last time.

The state's key witness in the Lizzi Marriott murder trial stepped down from the stand June 16 but not before the defense assailed her credibility one last time as being riddled by lies and a "contrived truth."

"It's easy for you to lie, isn't it?" Defense attorney Joachim Barth asked Kathryn McDonough.

Barth continued to portray accused murderer Seth Mazzaglia as taking the fall for McDonough, his young but controlling ex-girlfriend. He claims McDonough is the one actually responsible for Marriott's death on Oct. 9, 2012.

The defense pointed to conflicting statements McDonough gave to police, defense attorneys, investigators and another witness – Roberta Gerkin – who was wearing a wire and recorded a conversation with McDonough.

"At the time," McDonough said, "I did lie for him."

Barth replied, "At the time you had lied and thrown Roberta Gerkin under the bus to try to diminish your culpability for the events in Portsmouth?"

McDonough previously testified that Mazzaglia strangled and raped Marriott after she spurned his advances and declined to share their obsession with bondage and sadomasochism. McDonough testified that she and Mazzaglia put Marriott into a suitcase, duct-taped it shut, and drove to Portsmouth where they dumped her body into the Piscataqua River at Peirce Island.

Marriott's body has never been found.

McDonough, 20, is serving one and a half to three years in prison in exchange for testifying against Mazzaglia. As Barth revisited some of the lies she previously told, she insisted she was now telling the truth to jurors in Strafford County Superior Court in Dover N.H.

"We have heard you talk about lying to the police," Barth said Monday.

"I did lie to the police," McDonough said.

"Lying to us," Barth added.

"I did lie to you guys," she said.

In a last effort to impeach the credibility of the witness, the defense then reminded jurors of the lies that McDonough told in a blithe manner during a recorded interview with defense attorneys days after the murder. This was the same person, Barth underscored during an earlier cross-examination, who was surfing fetish and porn websites the day after Marriott was murdered.

The defense tried to shred her testimony that she was a "submissive" in the relationship with Mazzaglia. In previous testimony, McDonough said she was scared senseless after Mazzaglia killed Marriott, because she thought she might be next. She testified that Mazzaglia had two sides, what she told the court was like "Dr. Jekyll and Mr. Hyde."

McDonough did acknowledge June 16 that some of the lies she told in 2012 were partly tied into the conspiracy – that Mazzaglia wanted to protect her. She said it was their hope that he would serve just five years in prison, and that they could reunite afterward.

The two – Mazzaglia and McDonough – wanted to one day move away and open up a renaissance faire-type of a bed and breakfast, according to the court testimony.

* * * * *

The trial is continuing in Strafford County Superior Court in Dover, N.H.

Related Lizzi Marriott Murder Trial Stories


Get more local news delivered straight to your inbox. Sign up for free Patch newsletters and alerts.

We’ve removed the ability to reply as we work to make improvements. Learn more here

To request removal of your name from an arrest report, submit these required items to arrestreports@patch.com.