FILE - Adam Montgomery, with defense attorneys Caroline Smith, far left, and Paige Pihl-Buckley listens during a hearing on Wednesday, Sept. 28, 2022, in Manchester, N.H. Jury selection starts Tuesday, Feb. 13, 2024 Montgomery, accused of killing his 5-year-old daughter and spending months moving and hiding her body. He is charged with second-degree murder in the death of his daughter, Harmony, who was reported missing in November 2021, nearly two years after police believe she was killed in Manchester. Her body has not been found. (AP Photo/Kathy McCormack, File)

CONCORD, N.H. (AP) — More than two years after a police chief begged for information to find a long-missing 5-year-old New Hampshire girl, her father faces trial on charges that he killed her and spent months moving her body before disposing of it.

The remains of Harmony Montgomery have not been found and her father, Adam Montgomery, pleaded not guilty in 2022. Jury selection for his trial began Tuesday in Manchester, New Hampshire.

“I did not kill my daughter Harmony and I look forward to my upcoming trial to refute those offensive claims,” Montgomery, 34, said in court last August before he was sentenced on unrelated gun charges.

He acknowledged he was an addict: “I could have had a meaningful life, but I blew that opportunity through drugs. I loved my daughter unconditionally and I did not kill her.”

Montgomery is charged with second-degree murder, abuse of a corpse, falsifying physical evidence, assault and witness tampering. The trial is expected to last about three weeks.

The case of Harmony Montgomery, who was born in Massachusetts to unmarried parents with a history of substance abuse, exposed weaknesses in child protection systems and provoked calls to prioritize the well-being of children over parents in custody matters. Harmony was moved between the homes of her mother and her foster parents multiple times before Adam Montgomery received custody in 2019 and moved to New Hampshire.

Harmony was reported missing in 2021 by her mother, who said she hadn’t seen the girl in more than two years.

“I’m begging the community. I don’t care if you saw this young girl a year ago and you think it’s irrelevant. Call us,” Manchester police Chief Allen Aldenberg first told the public at a news conference on New Year’s Eve 2021, setting up a 24-hour tipline. Photos of Harmony were circulated widely on social media.

Police later believed the child had been killed in Manchester in 2019.

A key prosecution witness is expected to be Adam’s estranged wife, Kayla Montgomery, who is serving an 18-month prison sentence after pleading guilty to perjury charges. She agreed to cooperate with prosecutors.

According to an affidavit, Kayla Montgomery told police that her husband killed Harmony on Dec. 7, 2019, while the family lived in their car. Kayla Montgomery, who was Harmony’s stepmother, said he was driving to a fast food restaurant when he turned around and repeatedly punched Harmony in the face and head because he was angry that she was having bathroom accidents in the car.

“I think I really hurt her this time. I think I did something,” he said, according to Kayla Montgomery.

The couple noticed Harmony was dead hours later when the car broke down, at which time Adam Montgomery put her body in a duffel bag, Kayla Montgomery said.

For the next three months, investigators allege, Adam Montgomery moved the body from container to container and place to place. According to his wife, the locations included the trunk of a friend’s car, a cooler in the hallway of his mother-in-law’s apartment building, the ceiling vent of a homeless shelter and an apartment freezer.

At one point, the remains were kept in a tote bag from a hospital maternity ward, and Kayla Montgomery said she placed it in between her own young children in a stroller and brought it to her husband’s workplace.

Investigators allege that Montgomery disposed of the body in March 2020 using a rented moving truck. Toll data shows the truck in question crossed the Tobin Bridge in Boston multiple times, but the affidavit has no other location information to indicate the location of Harmony’s body. Last year, police searched a marshy area in Revere, Massachusetts.