Meanwhile, police have asked New York's Sanitation Department for trash pickup and dumping records dating back to 1979, said Vito Turso, a spokesman for the department.
"We said we would search for those handwritten logs," he said. However, he said, businesses in the area could have hired private companies to haul away their trash, and "we would have no records of their pickup schedules."
The Patz case was the first of several high-profile cases that catapulted concern about missing children to the forefront of national consciousness.
The relative of Hernandez is concerned about what Etan Patz's parents must be going through.
"At this moment, they must be hoping this is the right guy, and they don't go through this again," the source said. "It's going to be like a nightmare for them, if it turns out it's not Hernandez."
"They must want to know the truth and get this over with," the relative added. "At least they will know."