DOVER, N.H. (CBS/AP) — The defense has rested in the trial of the 31-year-old New Hampshire man charged with raping and killing a University of New Hampshire student.

Seth Mazzaglia‘s lawyers put on their last witness just before noon Tuesday, the 19th day of testimony.

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

During testimony Monday, a private investigator said Mazzaglia’s then-girlfriend, 20-year-old Kathryn McDonough, told her Marriott died when the two women were engaged in consensual rough sex. Defense lawyers unsuccessfully sought a mistrial on Tuesday, saying prosecutors maligned the private investigator’s motives.

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McDonough has since testified that Mazzaglia choked Marriott after she rejected his sexual advances. She’s serving 1 ½ to 3 years in prison for hindering prosecution.

Closing statements are set for Wednesday.

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