A woman who died after being stabbed on Saturday in Amesbury, Massachusetts, was allegedly killed by her son, the Essex County District Attorney announced Sunday.
Authorities say John Brittan, 27, of Amesbury, killed his mom, Barbara Diehl-Peirce and injured his step-father on Saturday at 23 Chestnut Street.
Brittan was arrested and is facing charges of murder, assault and battery on a person over 60 and assault with intent to murder.
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"It's terribly sad, it's horrific," said neighbor Edith Maxwell. "I believe there hasn't been a murder in Amesbury since 2004."
The shocking turn of events was enough to rattle even seasoned crime novelist Maxwell.
"I write murder mysteries. I'm a mystery author. But this is real life, and it's just astonishing and heartbreaking," she said.
NBC10 Boston tracked down Brittan's father in Newburyport on Sunday. He didn't want to talk on camera but tells NBC10 Boston that his son suffers from schizophrenia and doesn't use medication for the illness. He also said his son lives with his mother in Amesbury.
Authorities responded to the Amesbury home around 4:06 p.m. for a reported stabbing and discovered the two victims.
Diehl-Peirce was airlifted to Boston Medical Hospital with life-threatening injuries where she later died. Her husband, whose name has not been released by officials, was taken to Portsmouth Hospital with serious but non-life threatening injuries where he continues to recover, according to the DA.
Neighbor Dacy Burns says she saw the flashing lights and heard the emergency sirens, saying, "Lots of K9 dogs, police officers, crime scene tape, that kind of stuff."
"It's Amesbury," she added. "This kind of stuff just doesn't happen."
Amesbury resident Steve Ianglois knows the couple who lives at the address where the violent attack took place. He tells NBC10 Boston the couple had been hard at work renovating their home.
"It's very quiet. We very rarely have problems or trouble. Speeding cars sometimes but never anything like this," Ianglois said of the area. "All of a sudden everyone just swarmed here, and I walked by and the police officer said I should get back in the house because the suspect was still on the loose."
While Brittan was later arrested, Ianglois and other neighbors continued to be bothered by the incident.
"This is strange," he said. "This is strange."
There was no immediate word on a possible motive.
Brittan is expected to be arraigned Monday in Newburyport District Court. It's unclear if he has an attorney.