Nathan Carman Upset with Grandfather, 87, for Having 25-Year-Old Mistress Prior to Murder, Says Aunt (Exclusive)

In 2022, a federal indictment filed in Vermont charged Nathan Carman with the murder of his mother and accused him of killing another family member.

"On December 20, 2013, Nathan Carman murdered his grandfather, John Chakalos, shooting him twice with [a semi-automatic rifle] while Chakalos slept in his Windsor, CT home," read the indictment, a copy of which was obtained by PEOPLE.

The indictment suggests this was all part of an effort to gain access to his grandfather's fortune, which was estimated to be around $42 million at the time of his death.

Nathan, who was 19 at the time, did gain immediate access to $450,000 after the death, but at the same time had a credit card, truck and apartment that was all paid for by Chakalos.

That is why one family member tells PEOPLE that they believe morality, and not money, was the motive.

"I think it really was that Nathan was angry at my dad having an affair,” Nathan's aunt Charlene Gallagher explains. “And not only was he cheating on his grandmother, which was a sin, he was also cheating with somebody that was around Nathan’s age.” 

Compounding that anger may have been the fact that Nathan's grandmother Rita had also died after a long battle with cancer a month before her husband's murder.

Nathan and his public defenders wrote about Chakalos' mistress in a 2022 motion for pretrial release.

The motion stated there were "plenty of other suspects," with a footnote identifying the mistress as one. Police never declared her a suspect and she was never charged with murder.

"Mr. Chakalos had visited an adult erotic store prior to his murder. The weekend prior, he had taken a much younger employee to a casino in Connecticut where he engaged in a sexual relationship, likely for money," the motion read.

It went on to state that "Mr. Chakalos had also engaged in relations with this same young employee at his house in New Hampshire," note she had a previous arrest and that police had "interviewed her multiple times."

Nathan had developed a religious fervor around this time, as described in the Netflix documentary The Carman Family Deaths, which described one instance where Nathan stood at the altar of his church and spent five hours asking for forgiveness.

He was never arrested for the murder of his grandfather due in part to Chakalos' neighbor telling police they heard a gunshot around 2 a.m., and surveillance video confirming Nathan was home at his apartment at that time.

Nathan had returned to his apartment after having dinner with his grandfather on the evening of Dec. 19, 2013.

After dinner, Nathan drove his grandfather back to his home in Windsor, where Chakalos was found murdered by one of his four daughters the following morning.

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Family members, with the exception of Nathan's mother, soon suspected Nathan had murdered his grandfather.

He had been the last person to see Chakalos alive and had recently purchased a semi-automatic rifle, which used the same ammunition used by the killer.

The weapon was never found, and Nathan had also removed the GPS from his truck and disposed of his computer's hard drive, investigators soon learned, making it difficult to gather evidence.

Furthermore, there was no sign of a break-in at the home and nothing appeared to have been stolen, police determined after investigating the scene.

Nathan was never formally charged, as federal prosecutors lacked jurisdiction.

A year after being indicted, Nathan hanged himself in his jail cell.