(NewsNation) — The investigation into a missing 5-year-old New Hampshire girl, not seen since 2019, has stretched from New England down to Florida.

Investigators traveled to Florida to speak to Harmony Montgomery’s relatives.

The trip south comes after investigators searched the wetlands in Revere, Massachusetts, last Friday.

While authorities didn’t disclose if they found anything in the marshy area, NewsNation law and justice contributor Jennifer Coffindaffer said it would’ve been difficult to find anything there now.

“This would be extremely difficult to find anything here after this long period of time. And because of the marshland — just the environment being wet and salty, and all the issues that they would face in a body surviving that condition,” she explained.

Harmony’s father, Adam, was arrested in October 2022 in connection with her disappearance. He has been charged with second-degree murder in connection to her presumed death. He faces trial this summer.

Adam is expected to go to trial in August, which Coffindaffer said will be “more challenging,” as Harmony’s body hasn’t been found yet.

“Anytime you don’t have a body, it’s just more difficult to prove the death and the manner of death, even though there is going to be eyewitness testimony as to what happened. But a body or any part of her body would be very helpful for that prosecution, she explained.

Authorities didn’t know Harmony was missing until November 2021. In August 2022, police announced that they believed she was killed in Manchester in early December 2019.

Harmony lived with her father and stepmother before her death. Her father had been jailed over child abuse charges and her stepmother, Kayla Montgomery, had been accused of lying to a grand jury and illegally collecting food stamps in Harmony’s name.

Harmony had been surrendered to the child welfare system in Massachusetts by her biological mother and stepmother while her father was previously in prison. After jumping from foster home to foster home, Harmony was again placed in her father’s care.

The girl’s disappearance sparked a state investigation into why her father was awarded custody despite his violent history.