DOVER — Seth Mazzaglia, the Dover man charged with killing University of New Hampshire student Elizabeth Marriott in October last year, has been indicted on three more charges including a plot to escape jail.



Charges include conspiracy to commit tampering with witnesses and informants, conspiracy to commit falsifying physical evidence and criminal solicitation to acquire implements for escape and other contraband.



On Nov. 14, prosecutors presented a grand jury with evidence at Strafford County Superior Court alleging:







■ Mazzaglia discussed how the murder of Marriott could be covered up; told police Marriott died accidentally during a consensual sexual encounter;



■ Made up a story that Paul Hicock, a witness in the case, killed Marriott;



■ Wrote letters in jail expressing his desire to kill Hicock and material witness Roberta Gerkin;



■ Recruited a fellow inmate to deliver letters to his girlfriend, Kathryn “Kat” McDonough, in which he set forth plans to abscond from custody and flee to another country with her.





Prosecutors claim Mazzaglia conspired to commit falsifying of physical evidence by:







■ Using McDonough's phone to create false text messages;



■ Deleted messages on his and McDonough's phone;



■ Concealed Marriott's body in a suitcase and a tarp;



■ Removed her dead body from their apartment and transported it to Peirce Island in Portsmouth.







He and McDonough disposed of Marriott's phone and GPS. Afterward, they abandoned her vehicle on the University of New Hampshire's campus in an attempt to cover up their crimes, according to court documents.



On the criminal solicitation charge prosecutors allege Mazzaglia solicited Ryan Bachman while Mazzaglia was in official custody for Marriott's death, recruiting him to assist in a planned armed and violent breakout from custody. Mazzaglia provided Bachman with detailed plans for the escape and provided him with access to his bank account, prosecutors said.



McDonough was also charged in Marriott's death and pleaded guilty in July to lying to police about Marriott's murder. McDonough, 19, was sentenced on charges of conspiracy, witness tampering and hindering prosecution. She was ordered to serve three consecutive jail terms of between 3� and 7 years — a potential incarceration of up to 21 years.

Marriott's disappearance last year prompted authorities, friends and family to launch a frantic search of the Seacoast area, including Peirce Island.