The family of accused Gilgo Beach serial killer Rex Heuermann has gotten a helping hand from an unexpected source: The daughter of a notorious jailed murderer.

The daughter of Rex Heuermann, the accused Gilgo Beach serial killer, told a new documentary she believes her father "most likely" responsible.

The man's daughter believes he's "most likely the Gilgo Beach killer" based on evidence and information in the case, according to the family's attorney.