Officials with the NYPD said James Currie, 37, will be arrested on a charge of concealment of a human corpse when he returns to New York after fleeing to Thailand.
The 7-month-old child, identified by police as Mason Saldana, was discovered on an embankment of the East River under the Brooklyn Bridge on Sunday wearing only a diaper.
Authorities say Currie picked the child up from his mother's home on Saturday. Currie then took the child to his apartment in Co-Op City in the Bronx.
Twenty-four hours later, police say Currie was spotted leaving the residence with what appeared to be a backpack rigged like a baby carrier and covered with a blanket.
Currie was later spotted walking near South Street Seaport roughly an hour before his son was located in the river by tourists. The next day, he hopped on a flight to Thailand.
Authorities received a 911 call from the child's mother Monday evening to report that her child wasn't dropped off at day care.
Police said at some point during the call, the mother brought up that she heard about a child thrown into the water on the news, and she started crying.
"I don't think anyone could listen to the call without the blood curdling," NYPD Chief of Detectives Dermot Shea said. "This is clearly something no parent should have to live through."
There is no definitive cause of death at this time, but police say charges against Currie could be upgraded.
One person who lives on the same floor as Currie in Co-op City described him to be typical, friendly, no concerns, though neighbors are learning that he may have a dark side.
"You don't expect someone like that living next-door to you," said a neighbor named Yvonne after learning Currie is accused in the case.
"He was friendly, he would say hello and goodbye," she said.
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