The search for Harmony Montgomery, a New Hampshire girl who disappeared in 2019 at age 5 but was not reported missing until late last year, is now considered a homicide investigation, authorities said Thursday.

Authorities have concluded that Harmony was murdered, New Hampshire Attorney General John Formella said at a news conference.

"Our commitment to bringing Harmony home has not wavered, nor will it," said Manchester Police Chief Allen Aldenberg.

Police first became aware that Harmony might be missing when they received a call from the girl’s mother, Crystal Sorey, in November. She had been unsuccessfully trying to locate the girl for months, police said.

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Police said they contacted Harmony’s father, Adam Montgomery, and other family members by the end of December. According to court documents, police told him that Harmony had not been seen in more than two years and there was concern over whether she was still alive.

Hampton Beach, Portsmouth, Manchester news

The investigation of a New Hampshire girl who disappeared in 2019 is being investigated as a homicide.

Harmony’s father and stepmother, who have since pleaded not guilty to charges related to her well-being, told police that Adam brought Harmony to be with her mother in Massachusetts around Thanksgiving 2019. Her mother said she last saw her daughter during a phone video conversation at around Easter that year.

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In January, police said they believed that Harmony had disappeared between Nov. 28-Dec. 10, 2019.

Adam Montgomery, 31, was indicted in March on an assault charge alleging that he struck Harmony in the face in July 2019. He pleaded not guilty and has been in jail since January.

Kayla Montgomery, 32, was charged with theft by deception after police said she falsely claimed that her stepdaughter was living with her in order to collect welfare benefits. She has pleaded not guilty and was released on bail.

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Law enforcement agencies searched the couple’s former home on June 14. They completed a separate search on Jan. 10 of a home in Manchester that was the girl’s last known residence.