A beloved Scarsdale community advocate worried about her troubled and socially awkward son for years — until he allegedly snapped and stabbed her to death in her own home, a family friend told The Post.

Marian Green, 71, struggled for years to find a productive path for her 26-year-old son, Chester Green, encouraging him to pursue his talent for blacksmithing and taking him along to political and community meetings to spark his interest, close pal Nancy Meyers Silverman said Thursday.

It was the first murder in the Westchester County suburb — long one of America’s wealthiest communities — in more than a decade.

Chester Green 26, is charged with beating and stabbing his mother to death in her Scarsdale home. snapchat/charredemotions

“She was worried about her son, she really was,” said Silverman, 57. “She wanted him to be a productive part of society, and she was concerned because I know her husband passed away a couple of years ago, and she just wanted Chester to thrive.

“There was never a meeting where we didn’t discuss Chester, or she didn’t bring up wanting the best for him,” she added. “He did have some sort of condition.”

Police said Marian Green was beaten and stabbed to death in her Scarsdale home bertween July 5 and July 7. Luiz C. Ribeiro for NY Post

Her efforts ended in tragedy, when police said Chester allegedly beat and stabbed his mother to death inside her $2.5 million home in the wealthy Westchester County suburb over the weekend.

Westchester prosecutors said he allegedly killed his mom between July 5 and 7, and was arraigned on a second-degree murder charge on Wednesday and ordered held without bail.

The first images of the accused killer show him shirtless, with long brown hair and piercing eyes.

A former classmate of Chester said as soon as she heard someone was killed in the house, they immediately believed the 26-year-old was behind it — since he was known as an odd, mean and violent kid.

However, Silverman was less suspicious. She said her friend’s son was always a bit off, attending special education classes in school and never quite fitting in with others in the upscale community — but never showed signs of violence.

The Scarsdale house where Marian Green was found beaten and stabbed to death over the weekend. Kyle Mazza/Shutterstock

“I don’t know exactly what you know his diagnosis was, but nothing that would point to this situation,” she said. “Maybe he was a little slow developing, but there was nothing that would point to this.

“He was a health freak a little bit – just really into his health and not eating bad food or drinking from plastic water bottles,” Silverman added. “He possibly dabbled with drugs, I don’t know how much or with what. I know he was thinking at one point of opening a cannabis store. He was off the beaten track, not a mainstream Scarsdale kid at all.”

She said Chester was Marian Green’s only child and the two lived alone since his father died years ago.

Family friend Nancy Meyers Silverman said Marian Green struggled with her troubled son for years. snapchat/charredemotions

Marian was a staunch advocate for disabled people and special needs children, and acted as the chair of the village’s Advisory Council for People with Disabilities, Lohud reported.

Silverman said she tried to include him in her social circles, but it didn’t take.

Chester’s former elementary and middle school classmate told The Post he was “known to be loud and always screaming and saying mean things.”

Chester Green was “not a mainstream Scarsdale kid at all,” family friend Nancy Meyers Silverman said. Obtained by NY Post

In one instance, Chester carpooled with the classmate and her 6-year-old sister to ice skating lessons and smacked the youngest because she was “being loud,” she recalled. 

“We obviously stopped carpooling with him then,” she said. 

“My mom told me also in elementary school because I don’t remember this was so long ago, but she told me that I came home crying because he told me he was gonna murder my whole family.”

Marian Green was allegedly killed by her son. Scarsdale.org

The former classmate described Chester as an “off and weird” kid who frequently repelled people in school because he was scary. 

“The thing with Chester, we all knew he was very off and weird, and just didn’t act right. It honestly was sad. I feel like we kind of tried to ignore him,” she said.

“When we first saw in the news that a woman had been found dead in that house, we all assumed it was him because he’s always been insane,” she added.

Police on the scene of a fatal stabbing in Scarsdale. Kyle Mazza/Shutterstock

 “He had a hobby where he was really interested in swords or knives or something, and it was creepy because he would threaten people and say mean things. The fact that he was interested in sharp objects was very scary, especially seeing what happened now.”

She added that Marian always tried to be there for Chester and was “always so nice.”

“I don’t know what is going on behind closed doors, but I feel like she was a good mother to him, and I feel like she tried to do everything she could, and unfortunately, he was just the way he is.”

Chester Green is being held at the Westchester County Jail and is due back in court Aug. 5.

Scarsdale has been ranked the wealthiest suburb in the US for three straight years by MoneyLion, with an average annual household income of over $612,000 — and with violent crime extremely rare.

The last homicide in the tony village was in January 2016, when Julius Reich brutally killed his wife, pediatrician Robin Goldman, in their home. 

The couple was in the midst of a nasty divorce when Reich snuck upstairs and ambushed Goldman while she showered in their Lincoln Road home, stabbing her 22 times with an 8-inch kitchen knife. 

Reich then went downstairs, called 911, and was arrested. 

He is now serving a 20-year prison sentence for first-degree manslaughter.