NEW YORK (AP) — A man shot his hedge fund founder father to death inside his apartment near the United Nations headquarters after they argued over the son's allowance, police said Monday.

Thomas Gilbert Jr. was arrested on charges of murder and criminal possession of a weapon in the death of Thomas Gilbert Sr. He was being held pending arraignment, and the law office representing him had no comment.

Police said Gilbert Jr. went to his parents' home on Manhattan's East Side on Sunday and asked his mother to go out to get him some food. About 15 minutes later, she got a "bad feeling" and went back, said Robert Boyce, the chief of detectives for the New York Police Department.

"She found Senior on the floor with a bullet hole in the head," Boyce said. "She also found a gun resting on his chest with his left hand covering it."

But Boyce said it was a staged suicide — his son was trying to cover up the killing.

Officers went to Gilbert Jr.'s West Side apartment, where they found magazines, loose bullets and a shell that matched the gun found at the scene, police said.

Gilbert Jr., 30, was in debt and had argued with his father, 70, over his allowance, police said.

In 2011, Gilbert Sr., a graduate of Princeton University and Harvard Business School, founded Wainscott Capital Partners Fund, which has $200 million in assets. Industry publication Hedge Fund Alert said the fund had a net return of nearly 25 percent in 2012.

Gilbert Jr. also attended Princeton, graduating in 2009 with a degree in economics. Authorities said he had no recent work history.

Gilbert Sr. worked on Wall Street for more than 40 years, according to his profile on Wainscott's website, and he previously co-founded Syzygy Therapeutics, a biotech asset acquisition fund. He also was founder and CEO of an online teacher education company called Knowledge Delivery Systems Inc.

Wainscott, which invests in biotechnology and health care stocks, had no immediate comment Monday. The fund focuses on stocks traded on large exchanges like the Nasdaq and New York Stock Exchange, and the minimum amount for investors is $500,000.

"We're not cowboys," Gilbert Sr. said in a November interview with the publication FINalternatives. "People say, 'This guy can be up 40 percent but then he can be down 40 percent.' We would rather be up 20 percent and not have any down months or down years."

The shooting was a rare act of violence in the Sutton Place neighborhood, a wealthy enclave just north of the United Nations.

Neighbor Pierre Gazarian remembered Gilbert as "incredibly courteous, elegant," and praised his "civility (and) caring."

"In a building in New York City, a lot of people barely say hello to each other," Gazarian said. "That makes the loss for some of us that much more painful."

Gilbert Jr. has a pending criminal case in the town of Southampton, on eastern Long Island.

Gilbert Jr., who has an address in the hamlet of Wainscott, was arrested Sept. 18 on a charge of criminal contempt. Southampton town police say he violated an order of protection issued in Brooklyn in June. Police say he confronted a man named Peter N. Smith at Sagg Main Beach in Sagaponack on Sept. 1.

He has pleaded not guilty and has a Feb. 2 court date scheduled.