DOVER, N.H. — The photograph of a beaming Elizabeth “Lizzi” Marriott was taken on Mother’s Day 2011, a frog she rescued from the family’s pool cupped in her hand. A year and a half later, Seth Mazzaglia raped her, killed her and threw her body in a river after she rebuffed his sexual advances.

Mazzaglia was sentenced Thursday to life in prison without chance of parole after more than a dozen of Marriott’s family members and friends tearfully and angrily lamented what he took from them.

Her father, Robert Marriott, walked around the courtroom holding aloft an enlarged version of his daughter’s picture for all to see, a smaller version of which was used at trial. Marriott said it underscored the melancholy he felt that such a joyful memory became part of the legacy of a “horrible” trial.

“I wish that good would triumph over evil, but you are proof beyond any doubt how untrue that is,” Bob Marriott told Mazzaglia.

Some family members replayed the agonizing months and hours since Marriott’s disappearance, while others recalled the quality of her life before she was killed on Oct. 9, 2012, at age 19.

The aspiring marine biologist from Westborough, Massachusetts, had started her sophomore year at the University of New Hampshire only five weeks earlier. She had befriended Mazzaglia’s girlfriend, Kathryn McDonough, at a local department store where they both worked. McDonough, the key witness at trial, testified that Mazzaglia, 31, demanded she lure Marriott to their apartment as a sexual offering for her domineering boyfriend.

McDonough said after Marriott twice rejected his sexual advances, Mazzaglia looped a rope over her head from behind and strangled her until she was unconscious. McDonough said he then raped Marriott’s motionless body as he yelled expletives at her.

Marriot’s mother, Melissa Marriott, told Mazzaglia before the sentence was announced, “I want you to know that I unequivocally hate you.”

She continued in a firm voice: “You are a cowardly, despicable person. You stole our smart, vivacious, beautiful daughter from us. You murdered Lizzi, raped her lifeless body and then threw her away because Lizzi had the self-confidence and the self-esteem to say no to you.”

An uncle, Tony Hanna, called Mazzaglia “a twisted individual who brought only darkness and pain into this world.”

Mazzaglia spoke briefly.

“I did not rape and murder Elizabeth Marriott,” he said. “However, I do understand the Marriott family’s pain and I did play a part in covering up her death, a mistake I tried to correct when investigators came to me and I showed them exactly where I left Lizzi’s body. Unfortunately, they were unable to recover her and for that I am truly sorry. My heart goes out to the Marriot family and I am very sorry for their loss.”

During a brief recess before he was sentenced, Mazzaglia’s mother, Heather Mazzaglia, asked if she could speak with the Marriotts. She went into a conference room and gave Bob Marriott an extended hug while sobbing. She gave him a folded note and told an Associated Press reporter upon exiting that she told him “only that I’m sorry.” She also hugged Elizabeth’s brother, Robert Marriott Jr., who went with his father into the room.

Later, clutching a red Bible to her chest, she spoke privately with Melissa Marriott, who would not reveal what was said.

At least eight of the jurors who convicted Mazzaglia also were in attendance.

McDonough initially told investigators that Marriott died while the two women were engaged in consensual rough sex. Granted immunity from prosecution, she later changed her story.

McDonough is serving 1 1/2 to 3 years in prison for hindering prosecution and witness tampering.

Bob Marriott said after court that he has conflicting feelings about McDonough.

“I have a lot of reason to very much dislike her and her involvement in what happened to my daughter,” he said. “I also have a lot of sympathy for the situation she was in and what she was put through by that person we just sent to jail.”