DOVER, N.H. (AP) – The former girlfriend of a man accused of raping and strangling a University of New Hampshire student says she still loved the defendant and wanted to protect him, even after she was granted immunity from prosecution.

Seth Mazzaglia, 31, is charged with first-degree murder in the October 2012 death of 19-year-old Elizabeth “Lizzi” Marriott, of Westborough, Massachusetts.

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Kathryn “Kat” McDonough, the state’s star witness, originally told defense investigators that she and Marriott were engaged in rough sex involving restraints when Marriott died. She told jurors this week that Mazzaglia killed Marriott when she rejected his advances.

McDonough, 20, testified that even after being given a grant of immunity for her testimony about Marriott’s death at a grand jury investigation in February 2013, she still loved Mazzaglia and wanted to protect him.

“At the time I was more worried about not being able to see him again,” she testified Friday. “But I knew if I were to lie to them, it would be even longer before I could see him.”

McDonough spent two full days this week being questioned by prosecutor Peter Hinckley, and Friday marked her second day of cross-examination by Defense attorney Joachim Barth.

Barth has spent much of his cross-examination attempting to get McDonough to admit she was driven by the voices in her head of five imaginary characters she created. She acknowledged she created them to mask her own weaknesses during childhood and adolescence but was unwavering that the characters did not influence her thinking.

“I didn’t actually have personas,” McDonough said. “I didn’t have split personalities.”

Asked why she didn’t tell the grand jury about her characters, McDonough said she answered the questions she was asked.

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“It was the first time I had told the truth about how Seth murdered Lizzi,” she testified. “I was scared. … I was talking about a lot of things that happened.”

McDonough has testified about her sadomasochistic relationship with Mazzaglia, who she began living with four months before she graduated high school. She said he was preoccupied with finding another woman to join their sexual relationship and instructed her to solicit one on fetish websites.

McDonough said that after she left to teach a 12-day theater camp in August 2012 and failed to find him a sexual surrogate during her absence, he punished her with brutal sex in which he bound, slapped and pinched her and pulled her hair. She said he also outlined a second punishment: He told her to bring a friend of hers to offer him as a sex slave.

That friend was Marriott, her co-worker.

McDonough testified that Marriott willingly played a game of strip poker with the couple the night of Oct. 9, 2012, but twice refused Mazzaglia’s sexual advances. As the two women sat with their backs against a futon watching a movie, McDonough said Mazzaglia looped a rope around Marriott’s neck and strangled her until she was unconscious. McDonough said he then raped her motionless body.

The couple then used Marriott’s car to drive to Peirce Island and dump her body into a river that feeds into the ocean, she said. It has not been recovered.

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