The wife of a wealthy hedge fund founder who was allegedly gunned down by their adult son told a 911 dispatcher her husband had been shot by "my son, who is nuts," jurors in New York heard Tuesday.

Prosecutors played the emergency phone call made by Shelley Gilbert, who is reluctantly testifying in Manhattan Supreme Court against her son, Princeton graduate Thomas Gilbert Jr.

"My husband is, I think, dead. Please rush," Shelley Gilbert told the 911 dispatcher about Thomas Gilbert Sr. on Jan. 4, 2015. "He's dead, I think."

The dispatcher then passed the call on to a paramedic who instructed Shelley Gilbert on how to do chest compressions. While she attempted the life-saving maneuver, she told 911 that it would be fruitless.

"I think he's been dead. He's been shot," she said.

The male EMS appeared to be stunned: "He's been shot?"

That's when the 911 dispatcher came back on the line to ask Shelley Gilbert who pulled the trigger.

"My son, who is nuts, but I didn’t know he was this nuts," she replied.

The son is accused of killing his father after his parents cut his allowance.

Thomas Gilbert Sr. had just turned 70 when he was killed inside his luxurious eighth-floor apartment on the East Side of Manhattan.

The son, a 2009 Princeton University graduate, told police at the time of his arrest that he was making $3,000 a month working in finance, court records showed.

But police said Thomas Gilbert Jr. was in debt and had no recent work history before his arrest.

The parents were paying their son's $2,400 monthly rent, police said. He had been receiving a $600 weekly allowance — an amount that Thomas Gilbert Sr. was lowering to $400 a week just before his slaying, police said.