DOVER - A second person has been arrested in connection with the disappearance and death of University of New Hampshire sophomore Elizabeth "Lizzi" Marriott, 19.

On Monday, New Hampshire Attorney General Michael A. Delaney announced the arrest of Kathryn McDonough, 19, of Portsmouth, on felony charges of hindering apprehension or prosecution and conspiracy to commit hindering apprehension or prosecution.

Police arrested Seth Mazzaglia, 29, of Dover in October and charged him with second-degree murder for allegedly strangling and/or suffocating Marriott in his Mill Street apartment.

Sources have confirmed to the New Hampshire Union Leader that McDonough was Mazzaglia's live-in girlfriend at the time of the alleged murder.

"Credible information" led police to the waters around Peirce Island in Portsmouth to search for Marriott's body in the days, weeks and months since her alleged murder, but her body has not been found.

Friends told the Union Leader previously that Marriott was on her way to visit a friend in Dover on Oct. 9, the night police believe Mazzaglia killed her. Marriott had met the friend, believed to be McDonough, while working at the Target store in Greenland.

Both Mazzaglia and McDonough were active in local theater organizations, including the Garrison Players in Dover, according to information on the organization's website.

McDonough is scheduled to be arraigned on the felony charges in Derry District Court on Dec. 26.

Documents related to Mazzaglia's arrest have been kept under seal pending an indictment against him. He is currently being held without bail.