Police say Thomas Gilbert was shot in the head in his Manhattan apartment on Manhattan's posh Beekman Place

Thomas Gilbert, a 70-year-old hedge fund founder, was shot dead in his swanky New York apartment Sunday, and his 30-year-old son, Thomas Gilbert Jr., was taken in by police for questioning after the son had barricaded himself inside his apartment, say reports.

The two had been arguing in the elder Gilbert’s bedroom at around 3 p.m., sources tell the New York Post. The victim’s wife called 911, according to the paper.

The Associated Press reported Thomas Gilbert was shot in the head and pronounced dead at the scene.

The son had fled the murder seen on foot, officials told the New York’s Daily News, which also reported that a handcuffed Gilbert Jr showed no emotion as he was escorted by police from his 18th Street apartment to the 17th Precinct house for questioning at around 11 p.m.

No motive is known. The shooting was a rare act of violence on Beekman Place, a tony enclave just north of the United Nations on the East River between 49th and 51st Streets. The two-block street has been home to composer Irving Berlin, supermarket scion and arts patron Huntington Hartford and the fictional character Auntie Mame.

In 2011, Gilbert founded Wainscott Capital Partners Fund, which has $200 million in assets and focuses on the biotech and health care industries.

“He was a pillar on Wall Street – somebody everyone looked up to,” Hector Torres, 33, a neighbor of Gilbert’s told the Post. “Very nice gentleman They seem like a normal family. Every time I saw him in the elevator, he would say, ‘Hi.’ He would ask how I was.”