A jury has convicted a 31-year-old man of killing and raping a University of New Hampshire college student following a trial filled with lurid details of sexual domination, experimentation and violence.

The jury in Strafford Superior Court returned its verdict Friday, finding Seth Mazzaglia guilty of first-degree murder in the death of 19-year-old Elizabeth "Lizzi" Marriott of Westborough, Massachusetts, in October 2012. 

The key witness, 20-year-old Kathryn McDonough, was Mazzaglia's girlfriend when she lured Marriott to their apartment. She testified that Mazzaglia wanted another woman to join their sexual escapades, which included bondage and discipline.

McDonough first told investigators that Marriott died during rough sex between the two women that involved restraints. After getting immunity from prosecution, McDonough changed her story and said Mazzaglia strangled Marriott then raped her.