The Montgomery family had been living in their Chrysler Sebring for about 10 days before 5-year-old Harmony was fatally beaten by her father for having bathroom accidents in the car, according to a newly unsealed affidavit.
The beating was the third time that Adam Montgomery got “upset” and struck his daughter “in the face/head with a closed fist” after having a potty accident in the car, an affidavit states. On Dec. 7, 2019, as the family was on their way to Burger King, Montgomery allegedly saw red.
Still driving, the 32-year-old father turned around in his seat and “delivered sets of three-to-four blows with a closed fist” to Harmony, who was in the back seat. The affidavit states that the attacks occurred three times “over the course of a few minutes.” After the final blow, Montgomery allegedly turned to his now-estranged wife, Kayla, and said: “I think I really hurt her this time.” It is not immediately clear if the other two children were in the car when the murder occurred.
Moments later, “Harmony began making a moaning type noise which went on for roughly five minutes and then stopped.” When the family finally realized Harmony “was not breathing,” Montgomery allegedly placed her lifeless body in a black and red Under Armour duffle bag he had in the trunk, the affidavit states.
It would take another two years for authorities to learn that Harmony was even missing—spurring a lengthy investigation that found a pattern of alleged abuse and serial criminality. Last October, Adam Montgomery was arrested and charged with second-degree murder in connection with Harmony’s death. At the time, however, prosecutors were scant with details about how the child died or how her father allegedly took steps to “conceal” her body afterward.
On Tuesday, authorities released the Oct. 25, 2022, affidavit against Montgomery, finally shedding light on those details, including how Kayla’s decision to turn on her estranged husband broke the case wide open. The unsealed affidavit comes just weeks after Montgomery was convicted of six firearms-related charges in a separate case.
During the trial, Kayla testified against Montgomery, describing how she and her children were living in “chaos” and surrounded by drugs and guns in the weeks leading up to Harmony’s death. Kayla pleaded guilty last November to two felony counts of perjury after lying about her whereabouts the day Harmony went missing.
In a June 2022 interview after her arrest, Kayla told investigators that Montgomery had murdered Harmony—and that she was encouraged to “lie” about what happened multiple times.
The affidavit states it was Kayla who described Harmony’s death in the car, including that she and Montgomery did not stop the car or attempt to get the child medical attention when she stopped moaning after the attack. She detailed how after Montgomery put Harmony’s body into the duffle bag he “walked it back to the parking lot” of the apartment complex there they were parking their car at the time.
Afterward, the affidavit states, Kayla told investigators that the family stayed in her friend’s Audi “in the parking lot for two or three days over the weekend.” During that time, Montgomery was allegedly “keeping the bag with Harmony’s body inside the trunk of the vehicle, but also would leave it out on the snow to stop the decomposition of the body from happening.”
Over the next several months, Kayla told investigators, Harmony’s body was moved to several locations. While the family was at Kayla’s mother’s house through the end of December 2019, Harmony was allegedly placed “inside of a red cooler” that sat in the common hallway. Then, the family moved to a family shelter, where Harmony was allegedly placed in a ceiling vent in the bedroom.
Kayla told investigators that when the family rented an apartment in February 2020, Montgomery allegedly put Harmony in a plastic bin storage container and placed it in a refrigerator. At the same time, Montgomery also allegedly moved his daughter’s body into a Catholic Medical Center maternity bag.
The affidavit states that the final temporary hiding place was in a fridge at Portland Pie Company, where Montgomery temporarily worked as a dishwasher and cook.
But in March 2020, Montgomery had a friend rent a U-Haul. He then allegedly used the truck to move his daughter’s remains in the middle of the night. MassDOT records show that the U-Haul was captured on video crossing the Tobin Bridge in Boston at around 4:44 a.m. and returning about an hour later, the affidavit states.
“To date, Harmony’s remains have not yet been located,” the affidavit states.
Police were first made aware of Harmony’s disappearance in December 2021, when her biological mother, Crystal Sorey, reported her daughter “was missing and that she hadn’t seen [her] in over six months.” When authorities finally found Montgomery and Kayla on Dec. 31, 2021, he made several “made contradictory statements” about the whereabouts of his daughter.
At first, he indicated that she was fine before later admitting he had not seen her in two years after claiming Sorey had picked her up. Eventually, police say Montgomery refused to answer questions if he was “not under arrest.”