(NEW YORK) -- Missing University of New Hampshire student Elizabeth "Lizzi" Marriott is dead, and police have arrested a man in connection with her death, according to the state Attorney General's Office.
Seth Mazzaglia, 29, was arrested in connection with Marriott's death, but her body has yet to be recovered, authorities said during a news conference.
Police had established a crime scene on Pierce Island in Portsmouth, N.H. Friday night, where WCVB reported a body was found, and the New Hampshire Union Leader reported the police work was related to the search for Marriott.
Investigators were also searching a Dover, N.H apartment for evidence, according to the Metro West Daily News.
Marriott, 19, was last seen on Tuesday, and she texted a friend to say she would stop by another friend's home just after 10 p.m. but never arrived. She did not show up for her job at Target on Wednesday and was not in class on Thursday.
"This is a parent's nightmare -- not knowing," Marriott's father, Bob, told WCVB-TV, ABC's Boston affiliate before police found his daughter dead.
"There are so many what-ifs that I don't want to think about right now," Marriott said. "Her cell phone showed up in Dover, N.H., a little bit after 10 p.m. She made it to Dover, but she didn't make it to the house."
The UNH homecoming festivities, which are taking place this weekend, were halted for an announcement to ask fans for information and help.
Volunteers spent Friday distributing fliers with her photo, a description and a $10,000 reward for her safe return. A team of law enforcement officers including the FBI and the state Attorney General's Office had been searching Dover, Chester and Portsmouth, N.H.
Marriott's uncle, Anthony Hanna, told ABCNews.com on Friday that police were looking through Marriott's phone and computer for information to help with the search, but it's possible she was in a car accident. Marriott lives with Hanna and her aunt in Chester and commutes to UNH in Dover.
"We're not ruling out that she was an inexperienced driver and may have just driven off the side of the road. It's quite a distance. And we're trying to coordinate a search," he said.
Marriott, a marine biology major, has blond hair, blue eyes, and is about five-foot-five and 130 pounds. She drives a tan 2001 Mazda Tribute.
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