DOVER — Jury selection wrapped up Tuesday in the murder trial of a New Hampshire man accused of raping and killing a 19-year-old college student after his former girlfriend lured her to their apartment.

Authorities say 31-year-old Seth Mazzaglia strangled University of New Hampshire sophomore Elizabeth “Lizzi” Marriott on Oct. 9, 2012, at the Dover apartment he shared with his then-girlfriend, Kathryn McDonough.

Mazzaglia has pleaded not guilty in the case. Opening statements were set for Wednesday in Strafford County Superior Court.

McDonough, 20, is expected to be the key witness. She is serving a prison sentence for hindering the prosecution, witness tampering and conspiracy as part of a plea deal that hinges on her cooperation with the state.

Marriott, from Westborough, Massachusetts, had transferred to UNH five weeks before her death. She met McDonough while working at a department store not far from campus. Prosecutors say Mazzaglia and McDonough dumped Marriott’s body into the Piscataqua River off Portsmouth’s Peirce Island. Her body has never been found.

During jury selection, the judge called a juror chosen last week back into court Tuesday after she phoned the clerk’s office to say she had had a conversation about the case with a co-worker.

The juror told the court under oath that when she told her boss she would need time off for jury duty, he questioned how she could have been chosen given her personal history of domestic violence.

She said she didn’t mention the domestic abuse on the jury questionnaire because her ex-husband was verbally abusive but had never physically assaulted her.

Judge Steven Houran left the juror on the panel after she assured him she could keep an open mind and not let her experience sway her assessment of the credibility of the witnesses.

Prospective jurors had been warned that they are likely to hear graphic testimony about sex acts, including bondage and discipline and role playing.