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New Hampshire 8-year-old Harmony Montgomery has been missing since September 2019, and police are asking for anyone with details about her to come forward.

Prosecutors allege her father beat her to death on Dec. 7 of that year and charged him with murder almost three years later after a months long investigation.

No tip is too small, according to investigators, who set up a dedicated 24/7 tip line at 603-203-6060 for potential witnesses.

In January 2022, police in her hometown of Manchester, New Hampshire, arrested her father Adam on child abuse and endangerment charges in connection with a 2019 incident that left the partially blind little girl with a black eye as well as his failure to divulge her whereabouts to authorities when they contacted him last week. More. than10 months later, they tacked on murder and other charges.

Missing New Hampshire girl Harmony Montgomery

Harmony Montgomery, now 8, was reported missing last week, two years after she was last seen. (National Center for Missing and Exploited Children)

MISSING HARMONY MONTGOMERY: DAD ACCUSED OF GIVING PARTIALLY BLIND DAUGHTER BLACK EYE IN 2019, OTHER ABUSE

Harmony is about 4 feet tall and weighs around 50 pounds. She has blond hair and blue eyes. Because of visual impairments, she should be wearing glasses. She’s blind in her right eye.

Here’s a timeline of events:

September 2014

Adam Montgomery pleads guilty to charges of larceny, carrying a firearm without a license and discharging a firearm within 500 feet of a building in an armed robbery during which he allegedly shot a man in the head. 

Harmony is around four months old. Montgomery receives a sentence of 18 months behind bars, according to the Essex County Attorney’s Office in Massachusetts. 

Adam Montgomery

Adam Montgomery in an undated booking photo. (Manchester Police)

July 2018

Crystal Sorey loses custody of Harmony in Massachusetts, in part due to struggles with substance abuse.

Harmony begins bouncing in and out of foster care.

Feb. 22, 2019

Harmony’s father, Adam Montgomery, secures custody of his daughter, taking her out of Massachusetts’ foster care system, according to juvenile court records from Lawrence, Massachusetts. 

MISSING HARMONY MONTGOMERY: ADOPTIVE PARENTS' PUSH TO REUNITE SEPARATED SIBLINGS TRIGGERED SUSPICIONS

Around April 21, 2019

Harmony’s biological mother, Crystal Sorey, who did not have custody of Harmony, speaks with her daughter over FaceTime for the last time. 

Sorey later told investigators her daughter "seemed frightened" during the call.

June 7, 2019

Blair and Johnathon Miller begin fostering Harmony's younger brother, Jamison.

"From night one, in the bedroom, he asked where Harmony was going to sleep," Johnathon Miller told Fox News Digital.

July 2019

Adam Montgomery allegedly punches Harmony, who is visually impaired and blind in one eye, in the face, leaving her with a black eye. But police weren’t told about this until more than two years later, according to an arrest affidavit released on Jan. 5, 2022.

His uncle, Kevin Montgomery, told police about the incident in December 2021. At least two other family members knew of the black eye – Adam Montgomery’s wife, Kayla, and his brother, Michael, according to the affidavit.

Aug. 16, 2019

The Millers meet Sorey for the first time and offer to adopt Harmony if the need ever arises, according to Johnathon Miller.

They discuss Jamison’s strong bond with his sister and exchange numbers with Sorey, remaining in regular contact ever since, following up on Harmony and giving her updates on Jamison. They also frequently sought to connect the siblings over FaceTime, but each time Sorey told them Adam Montgomery wasn’t answering her.

MISSING HARMONY MONTGOMERY'S FATHER ARRESTED IN NEW HAMPSHIRE

November 2019

The Millers legally adopt Jamison. They also reach out to Sorey and say they want to send Harmony a Christmas gift from her little brother, but she tells them she’s again unable to reach Montgomery.

June 2020

Around the time of Harmony’s sixth birthday, Sorey tells the Millers she hasn't been able to reach Montgomery or her daughter.

July 2020

The Millers again make clear they are willing to adopt Harmony if there is a need.

March 7, 2021

Jamison asks his adoptive parents if they can adopt Harmony.

"I want to call her a Miller too," Johnathon Miller quoted his son as saying at the time.

NEW HAMPSHIRE POLICE ANNOUNCE 24/7 DETECTIVE-MANNED TIP LINE FOR MISSING 7-YEAR-OLD HARMONY MONTGOMERY

March 21. 2021

Kayla Montgomery takes the three children she shares with Adam and moves into her mother's apartment "due to domestic violence on her from her husband, Adam Montgomery," according to the request for a restraining order her mother filed month later.

Between October and November 2021

Adam Montgomery splits with his wife, Kayla, and checks into a sober house.

He later moved to Maine with another woman, according to court documents, based on Kayla Montgomery’s statements to investigators.

June 2021

With Harmony’s seventh birthday approaching, the Millers are still sending pictures of Jamison to Sorey and asking about the girl’s whereabouts. She tells them that on the child’s birthday, she woke up crying and said she wished her ex would stop avoiding her.

Missing Harmony Montgomery and her little brother Jamison Miller at a foster home more than two years ago

Missing Harmony Montgomery and her little brother Jamison Miller at a foster home more than two years ago.  (Courtesy Johnathon Miller)

The Millers celebrated Harmony’s birthday with cupcakes and sang "Happy Birthday," still having never met her.

July 2, 2021

Adam Montgomery allegedly shows up at his mother-in-law's home, where his now-estranged wife was sheltering with their children, and tapped on the window. Her boyfriend later claimed to have found a steak knife outside the same window and the mother-in-law filed for a restraining oder.

July 29, 2021

Sorey tells the Millers that she finally found Montgomery, but he immediately blocked her on social media, according to Johnathon Miller.

September 2021

Johnathon Miller says Sorey told him she’d made contact with one of Montgomery’s aunts, who told her she hadn’t seen Harmony since some point in 2019.

Shortly afterward, she reportedly saw Montgomery posting a lot of his belongings on Facebook Marketplace.

Sept. 16, 2021

The Millers begin attempting to contact Adam and Kayla Montgomery over Facebook but have no luck.

Blair Miller, a Washington-based news anchor for Boston 25, reaches out to New Hampshire’s Division for Children, Youth and Families. Sorey later tells them she finally heard back from the agency.

Nov. 16, 2021

Sorey discusses filing a missing person report for Harmony with the Millers.

Nov. 18, 2021

Manchester school officials reveal they have no records that Harmony has ever been enrolled there. Sorey reports Harmony missing to the Manchester Police Department.

The Millers again offer to take Harmony into emergency foster care if needed.

Dec. 27, 2021

New Hampshire’s Division of Children, Youth and Families notifies police that it is unable to locate Harmony

As a result, police officially open an investigation into her whereabouts and discover she "had not been physically seen since October/November 2019." She was supposed to be in her father’s care the entire time.

Dec. 29, 2021

Sorey sends a letter to Manchester Mayor Joyce Craig saying she planned to go to the media and pleading for help.

"She's supposed to be in 1st grade, he NEVER enrolled her into school this whole time," she wrote. "She's missed important doctors appointments shes had since a baby due to her disability in her eye.."

Crystal Sorey sent an email to Manchester Mayor Joyce Craig on Dec. 29 pleading for help in the case.

Crystal Sorey sent an email to Manchester Mayor Joyce Craig on Dec. 29 pleading for help in the case. (City of Manchester)

Dec. 30, 2021

Montgomery’s brother and uncle tell police they have concerns about Harmony’s welfare.

Kevin Montgomery, Adam Montgomery’s uncle, said around the time of the alleged 2019 assault he saw Harmony with a black eye. He told police that his nephew told him, "I bashed her around the house" as punishment after her little brother started crying.

He also told police he hadn’t seen his nephew or Harmony since a few months after that incident.

Dec. 31, 2021

Adam Montgomery’s estranged wife Kayla tells police she last saw Harmony near the end of 2019, when her husband said he was dropping her off with her biological mother, Sorey.

Police said the couple’s three other children were "all presently accounted for."

Kayla Montgomery also said she saw Harmony with the black eye in 2019 and that her husband allegedly blamed it on one of their other children.

Also on Dec. 31, police finally find Adam Montgomery and his new girlfriend sleeping in a car off Harvell Street in Manchester. 

After police questioned Montgomery, they alleged he gave them contradictory statements – including first claiming to have recently spoken to Harmony and then backtracking to say the last time was when he claimed Sorey picked her up around Thanksgiving 2019.

Then he allegedly stopped answering questions and told investigators, "I have nothing else to say … If I’m not under arrest, I’m leaving."

The Manchester Police Department publicly declares Harmony a missing child and asks for help from the public.

Jan. 2, 2022

Manchester Police visit a home where Adam and Harmony Montgomery once lived.

Authorities later said it had since changed hands, and the new homeowner was cooperating with investigators.

Jan. 3, 2022

Manchester Police Chief Allen Aldenberg holds a news conference asking for the public to come forward with any tips that could help find Harmony.

He announced a 24-hour police hotline to be manned by detectives at all times for anyone with information that may crack the case: 603-203-6060. Two local businesses and the Manchester Crimeline offer a reward of $12,500 for information that brings Harmony home.

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Jan. 4, 2022

Police arrest Montgomery in connection with the alleged 2019 black eye and on child welfare charges.

The search for Harmony is still ongoing, and the reward is increased to $33,000 and continues to climb.

Jan. 5, 2022

Montgomery waives his bail hearing and agrees to be held in preventive detention at the Hillsborough County House of Justice. 

The judge granted his petition for a public defender.

Kayla Montgomery, 31, was arrested in Manchester, N.H., on Jan. 6 and charged with welfare fraud. Hers is the latest arrest as authorities continue their desperate search for 8-year-old Harmony Montgomery, who last seen in Oct. 2019 and first reported missing last week. (Manchester Police Department) (New Hampshire DOJ)

MISSING HARMONY MONTGOMERY: STEPMOM ARRESTED, CHARGED WITH WELFARE FRAUD

Jan. 6, 2022

Manchester police announce charges against Adam Montgomery's estranged wife, Kayla Montgomery, for alleged welfare fraud. She is accused of collecting food stamps on behalf of Harmony until June 2021 despite not having seen the child since around November 2019.

Jan 12, 2022

MISSING HARMONY MONTGOMERY: MORE CHARGES FILED AGAINST STEPMOM

Prosecutors announce they've filed additional charges against Kayla Montgomery while downgrading one count of felony welfare fraud to a misdemeanor and adding a charge of felony theft by deception.

Manchester police also announce that the reward for information on Harmony's whereabouts has risen to $104,000 and that authorities have received more than 300 tips in the case.

"I would hope that it wouldn't take money for somebody to do the right thing, but people have different motivators in their life," said Manchester Police Chief Allen Aldenberg. "So if money is one of them, then come forward with some relevant and viable information and let us know."

June 14, 2022

Investigators search an apartment formerly used by Adam and Kayla Montgomery at 644 Union Street in Manchester. They are seen carrying out evidence, including an entire refrigerator, and searching around a manhole cover outside.

The current tenant, identified only as "Ginger," told Boston 25 News that investigators took the fridge, doorknobs and faucets and replaced them all with new ones. She said they also looked closely in the bedroom closet and cut out bathroom drywall to examine the pipes.

Oct. 24, 2022

New Hampshire Attorney General John Formella announces charges against Adam Montgomery in connection with this daughter's disappearance and suspected death.

Adam Montgomery has a shaved head in new mugshot

Adam Montgomery is accused of beating his little daughter   Harmony Montgomery to death months after, as a convicted felon, he convinced a family court to grant him custody. (Manchester Police)

They include second-degree murder, falsifying evidence, abuse of corpse and tampering with witnesses at a news briefing Monday, roughly three years after the missing Harmony Montgomery was last seen alive.

Adam Montgomery is accused of punching the little girl in the head on Dec. 7, 2019, recklessly causing her death and "extreme indifference to the value of human life."

This story will be updated as additional information becomes available.