NEW YORK - A father who threw his young child off the roof of a 52-story Manhattan apartment building in a murder-suicide did so on the first day that he was allowed to be alone with the boy amid an ugly custody battle with the mother, police officials said Monday.

"There was a history of domestic turmoil," Police Commissioner Raymond Kelly told reporters.

Dmitriy Kanarikov picked up his 3-year-old son at 10 a.m. Sunday at a Manhattan police precinct - a neutral site negotiated by the parents - to spend time with him for the first time "outside of some sort of institutional setting," Kelly said.

"He picked up the son and we all know now tragically he went to a building. . . . [and] took the son to the roof," the commissioner said.

"All indications are he threw him off and that's when he jumped himself," Kelly said.

A friend of Kanarikov had once lived in the building, which is a short distance away from Columbus Circle and Lincoln Center. Investigators recovered a security video showing the father and son entering without being stopped by the doorman, and located Kanarikov's Lexus parked outside.

Officers responding to an emergency call reporting two jumpers from the building on the Upper West Side around noon Sunday found Kanarikov, 35, of Brooklyn, and the boy on the lower rooftops of separate nearby buildings.

The man was pronounced dead at the scene and his son, Kirill Kanarikov, was pronounced dead at a hospital, police said.

A witness said the boy was wearing Christmas pajamas.

Luis Ortiz told the New York Post that he was at the hospital when paramedics rushed the boy there and that they were pumping his chest and working on him. "You could tell he was slipping away," Ortiz told the newspaper.

The motive behind the tragedy remained murky on Monday.

Kelly said there was no note found, and investigators have no evidence Kanarikov ever threatened to harm his son. However, at one point, he had told his wife that "unless she signed over the house to him and some undisclosed property, he was going to take the child," Kelly said.

Kanarikov and his wife married in 2009 and lived in Brooklyn, where their son was born a year later. They separated last year, and the mother and son moved to New Jersey and got an order of protection.

It was the second time this year that a parent and child were involved in a fatal plunge from a New York apartment building.

In March, a woman clutching her baby son in her arms plunged eight stories out of a Harlem apartment window to her death, but the 10-month-old survived. Authorities found a suicide note in her home.