DOVER, N.H. (CBS/AP) – A judge says a martial arts instructor allegedly “strangled or suffocated” a University of New Hampshire student who was last seen nearly a week ago.

WBZ NewsRadio 1030′s Bernice Corpuz reports

Twenty-nine-year-old Seth Mazzaglia of Dover was arraigned on second-degree murder charges Monday in the death of 19-year-old Elizabeth “Lizzi” Marriott of Westboro, Massachusetts.  He did not speak during a brief arraignment via video feed, and was ordered held without bail.

Elizabeth “Lizzi” Marriott

Police have declined to say what led to Mazzaglia’s arrest, but they said they have credible information leading them to believe Marriott’s dead.

Her body has not been found.

A Dover District Court judge revealed a new detail in the case Monday during the brief arraignment, saying that Mazzaglia allegedly “strangled or suffocated” Marriott on October 9.

Assistant Attorney General Jane Young said that the murder took place in an apartment on Mill Street in Dover. Young would not say whether additional arrests are expected.

Seth Mazzaglia. (Photo Credit: Dover, NH Police)

Marriott, a marine biology major, was last heard from on that day. Her cell phone was last used that night and her car was found at UNH.

Marriott’s family says she met Mazzaglia last summer when both were working at a Target store.

Crystal Childers, a former manager of the Hannaford’s supermarket in Dover, told reporters Monday that Mazzaglia used to come in and “stalk” some of the teenage girls who worked there as cashiers.

“You could tell he would always try and hit on the younger girls. Me, myself, being a manager, I used to have complaints about him coming in,” Childers said.

“He wasn’t all there. I wasn’t the only one who noticed that.”

Mazzaglia graduated from the University of New Hampshire in 2006 with a degree in theater. Friends have said they were shocked to hear of his arrest.

The next hearing in the case is set for Oct. 29.

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