NEW YORK (CBSNewYork) — A fatal shooting rocked a normally quiet East Side neighborhood Sunday afternoon.

The incident happened around 3:50 p.m. in an eighth-floor apartment at 20 Beekman St. near East 50th Street.

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Police said they found 70-year-old Thomas Gilbert with a gunshot wound to the head inside a bedroom.

Sources say a gun was recovered in the apartment, 1010 WINS’ Roger Stern reported.

Law enforcement sources say the shooting stemmed from a domestic dispute between the victim and his 30-year-old son.

Investigators identified the son as Thomas Gilbert Jr., CBS2 reported. Sources say police are trying to track Gilbert Jr. down for questioning.

Neighbor Christopher Kelly, who lives on the floor below, told WCBS 880’s Monica Miller he heard a thump at around 3:30 p.m.

“Almost as if somebody had dropped something heavy like a glass on the floor from the apartment above us,” he said.

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Many neighbors were stunned to learn of the shooting, Stern reported.

“Like everybody else I was shocked,” said Bernard. “Especially in this neighborhood you would never expect anything like that — such a nice building, such a nice neighborhood.”

“It’s upsetting just because this neighborhood is so safe,” Karen Bergreen told CBS2’s Valerie Castro. “…I feel bad for the victim and I hope this doesn’t mean an upping of crime in the neighborhood.”

Thomas Gilbert Sr. was the founder and president of Wainscott Capital Partners, a $200 million company based in New York City, Miller reported.

The Medical Examiner’s Office will determine the cause of death.

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