PORTSMOUTH - Kathryn McDonough told New Hampshire State Police last October that she and her missing friend Elizabeth Marriott had plans to "go to a nearby cemetery and take pictures of ghosts" on the evening of Oct. 9, according to a police affidavit unsealed Tuesday.
McDonough said she headed to the cemetery alone after briefly looking for Marriott, who never showed up to meet her.
That alibi - and other alleged statements - led state prosecutors to charge McDonough, 19, of Portsmouth in Rockingham County Superior Court with hindering apprehension and felony witness tampering.
Affidavits supporting McDonough's arrest on Dec. 24 were unsealed in 10th Circuit Court in Portsmouth on Tuesday in response to the state declaring that the records no longer needed to be impounded.
McDonough's live-in boyfriend, Seth Mazzaglia, is charged with Marriott's murder - the details of which remain a contentious point of debate for the victim's family.
Mazzaglia, 30, claimed that Marriott died at his Dover apartment during a consensual group-sex act with McDonough that involved asphyxiating Marriott's neck with a rope, according to police. A lawyer for Marriott's family, George Thompson, called Mazzaglia's version of events "hateful fiction" that have no basis in reality.
The body of the University of New Hampshire sophomore has not yet been found despite an exhaustive search along the Piscataqua River in Portsmouth by a variety of law enforcement agencies.
State police affidavits unsealed on Tuesday include claims by Mazzaglia that McDonough tossed evidence into dumpsters and submerged Marriott's body in the Piscataqua River in Portsmouth.
Mazzaglia told investigators that he dragged Marriott's body from his car to an overlook on Peirce Island, where he pushed it into the water, state police Detective Sgt. Sara Hennessey said in a sworn affidavit."When Ms. Marriott's entire body did not enter the water, McDonough completed the task, entirely submerging the victim's body," Hennessey said, summarizing Mazzaglia's account. "Afterwards, McDonough made a joking reference to 'Davey Jones's locker.'"
Mazzaglia also claimed that he "and McDonough have formal paramedic training," but neither one of them, "called for medical assistance at any point on the evening of Oct. 9," Hennessey said in the affidavit.
McDonough has not been charged with aiding Mazzaglia with the murder, or with disposing of Marriott's body and other evidence.
Defense lawyer Andrew Cotrupi suggested on Tuesday that Mazzaglia's account to police was not entirely grounded in fact.
"I think the evidence will be significantly different from the accounts some people have made," Cotrupi said.
Cotrupi and state prosecutors are due back in court on June 6 for a structuring conference, so that the court can begin to sort out potential trial dates, pre-trial motions or a possible plea deal. Cotrupi remained circumspect about whether his client will opt to plead guilty, or serve as a state witness in Mazzaglia's murder trial set to take place in Strafford County.
"Obviously, Kathryn is caught in a something well beyond what she thought was even possible," he said. "She has nothing but regret to be involved in any way" in the events leading up to Marriott's death, Cotrupi said.
State police were led to McDonough because of a single text message Marriott sent to a friend just hours before she went missing on Oct. 9.
At about 8:55 p.m., Marriott sent a text message to a friend, Brittany Atwood, telling her that she was going to her friend "Kat's" house, according to an affidavit.
"That was the last contact Ms. Atwood had with Ms. Marriott," Hennessey said in the affidavit.
McDonough was questioned twice by police on Oct. 12 while the search for Marriott was under way.
Chester police Officer Nicholas McLellan first questioned McDonough about Marriott's whereabouts that day. McDonough gave a more detailed account to Hennessey and state police Sgt. Jeffrey Ladieu during an interview at the Newington police station later that same day.
McDonough told police she headed off on foot to take pictures at a cemetery alone after Marriott never showed up at her apartment to join her. McDonough claimed that she remained at the cemetery until about 11:45 p.m. but had deleted all the photographs she had taken.
Before leaving for the cemetery, McDonough told police that Mazzaglia came home but left to go jogging. Mazzaglia, during a separate interview on Oct. 12, told police he went jogging on the night Marriott disappeared. He said an injury while running kept him out late, but then he began to provide details about how Marriott died in his apartment, an affidavit said.
He was charged with second-degree murder the next day.