A federal judge has set an October trial for the millennial real estate heir accused of killing his World War II hero grandfather and his mother in a bid to inherit millions and defraud an insurance company for more cash.

Federal prosecutors accuse Nathan Carman, 29, of gunning down his grandfather, John Chakalos, a former Army paratrooper and self-made multimillionaire, as part of a scheme to collect from the family trust fund. 

He received $550,000 after his grandfather's 2013 death and allegedly blew through it over the next three years. That's when, prosecutors say, he sank his own boat, killing his mother at sea and filing an $85,000 insurance claim.

Judge Geoffrey W. Crawford scheduled the trial on murder and federal wire fraud charges for Oct. 2-20.

VERMONT MAN ACCUSED OF SHOOTING WWII HERO GRANDFATHER, MURDERING MOM AT SEA DEMANDS GRAND JURY MINUTES

Chakalos Carman split

John Chakalos, left, served with distinction in the U.S. Army during World War II and later built a real estate empire in New England. His grandson, Nathan Carman, right, is accused of killing him in 2013 to claim an inheritance and then killing his mother as part of an alleged insurance scam. (Patrick Raycraft/Tribune News Service via Getty Images, AP Photo/Steven Senne)

Chakalos, in an online obituary, was described as a "self-made man" and real estate developer with a passion for philanthropy and family. A month before his suspected murder, his wife of 59 years died of cancer.

During the war, Chakalos served in the Philippines, where he "participated in numerous high-risk missions."

Carman, on the other hand, failed out of community college while Chakalos was paying for his truck and apartment, according to court documents. The grandfather also footed a bill for riding lessons and room and board for a pony.

"Put simply, the charged scheme involves money, murder and misrepresentations."

— Federal prosecutors

Prosecutors have accused Carman of shooting his grandfather with a rifle in December 2013. In 2016, prosecutors allege, Carman invited his mother, Linda Carman, to go on a fishing trip on his 31-foot boat named Chicken Pox.

VERMONT MAN NATHAN CARMAN, CHARGED WITH KILLING MOTHER LINDA CARMAN AT SEA, PLEADS NOT GUILTY

Nathan Carman with his mom, Linda Carman

Nathan Carman is accused of killing his mother, Linda Carman, in 2016, while at sea on a fishing trip to get his hands on her millions.  (Facebook)

It sank. His mother was never found. And a private vessel recovered Carman floating in a lifeboat in the Atlantic a week later.

Carman then filed an $85,000 insurance claim for the sunken boat, which the insurer denied and fought in court.

"Put simply, the charged scheme involves money, murder and misrepresentations," Assistant U.S. Attorneys Paul van de Graaf and Nathanael Burris wrote in a takedown of Carman's arguments in a pair of filings this week.

VERMONT MAN CHARGED WITH MURDERING MOM AT SEA OVER INHERITANCE MONEY AFTER BOAT SANK OF RHODE ISLAND COAST

Nathan Carman walks off a Coast Guard vessel in white jumpsuit

Nathan Carman arrives at the Coast Guard base in Boston Sept. 27, 2016, after surviving the sinking of his 32-foot fishing boat near Block Canyon, off New York, in the Atlantic Ocean. (Suzanne Kreiter/The Boston Globe via Getty Images)

Carman's lawyers made the unusual move of demanding grand jury minutes last week, and they have requested a bill of particulars surrounding his federal indictment.

Grand jury proceedings are typically kept secret, and there is a high burden to force the court to compel their disclosure, according to authorities.

Prosecutors argued the claims in his motions were insufficient.

"He offers no specific evidence that anything inappropriate took place during the grand jury proceedings," van de Graaf and Burris wrote. "Rather, he relies on flawed readings of the charges and the law."

VERMONT MAN CHARGED WITH MURDERING MOM AT SEA OVER INHERITANCE MONEY AFTER BOAT SANK OF RHODE ISLAND COAST

They added that routine discovery practices would also grant the defense copies of grand jury testimony from federal agents.

Read the government's opposition to Carman's motion for grand jury minutes (App users go here)

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While Carman has only been charged with one count of murder for his mother's death, prosecutors said they are still accusing him of killing his grandfather.

"The fraud scheme outlined in Counts One through Six charges Carman with committing two murders — the murder of his grandfather and the murder of his mother — to obtain access to millions of dollars in a trust fund and hiding his responsibility for those murders," they wrote.