Garbage disposal records from 1979 may help investigators find boy's remains.
Investigators are trying to determine whether they can track the remains of 6-year-old Etan Patz now that a suspect has made claims about where he tossed the boy's body in 1979.
New York City Police contacted sanitation officials last week, when Pedro Hernandez was arrested, asking if the department has records dating back that far regarding which trucks might have collected trash from buildings in the area, the Department of Sanitation told NBC News on Monday.
Police Commissioner Ray Kelly said Hernandez has told police that he put the boy's body in a trash bag and left it in an alley a few blocks from the SoHo bodega where he claimed to have strangled the boy.
It was the first day Patz had ever been allowed to walk alone to the school bus stop. He never made it, and his disappearance mystified the city for decades.
Sanitation spokesman Vito Turso told NBC News on Monday that the city does have handwritten log books about which trucks picked up trash in certain locations, and records of where those loads were dumped.
Turso said if city trucks collected the bag with Patz's body, it could have been taken by barge to the former Fresh Kills landfill on Staten Island. It also could have been transported to an incinerator that used to burn trash near Gansevoort Street on the west side of Manhattan.
Turso said there was also the possibility that the bag would have been collected as commercial refuse by a private hauler.
In that case, NYPD would have to identify the store and trace the hauler.
That trash, Turso said, could have gone to Fresh Kills, the former Fountain Avenue landfill in Brooklyn, or some other private landfill.
"We await further word from NYPD," Turso said.
The Department of Sanitation also has records that show where in its landfills trash was dumped, by date and location.
That could help narrow a potential dig for remains, if police decided to pursue it.
Hernandez, 51, was a stock clerk at the bodega at the time the boy disappeared.
Police said he told them he lured Patz to the store with the promise of a soda, and then killed him in the basement.
He was charged Friday with second-degree murder and has not entered a plea.
His lawyer, Harvey Fishbein, told the court that Hernandez is a schizophrenic and has had both auditory and visual hallucinations.
He has requested a hearing to determine his client's mental fitness.