Shannan Gilbert disappeared in May 2012 after she went to meet a client at Oak Beach. She met him on Craigslist for s-x work and later went to spend time with him. However, according to eyewitnesses, she unusually ran away and was never seen again until her body was discovered at the Gilgo Beach shores.
Her disappearance was what prompted an intensive search in the area and, subsequently, the discovery of five other sets of remains of the ill-fated shores. She was one of the ten victims, joining the other Gilgo Four, whose remains were discovered just months before Shannan’s disappearance.
Her mother, Mari Gilbert, was one of the very first people who raised concerns about a serial killer being on the loose in the Long Island area following Shannan’s doomed fate. However, in the following years, Mari herself fell victim to a horrible crime committed by none other than her daughter.
The other victims, whose remains were discovered through the search for Shannan, have been linked to Rex Heuermann, the infamous Long Island serial killer who lived a double life as a Manhattan-based architect. However, investigators couldn’t confirm how Shannan died, with some reports insisting that she wasn’t murdered.
Her mom, Mari, who lived the last part of her life fighting for justice, couldn’t even get to see it, as she herself was killed by her surviving daughter, Sarra. On July 23, 2016, Sarra, who was schizophrenic, came to Mari’s Catskills apartment. There, she brutally stabbed her mother 227 times before bludgeoning her with a fire extinguisher, reports The Sun.
John Ray, who represents the Gilgo Four victims, stated that Sarra, who lived around Mari, came over because she was hallucinating. According to a 2017 WNBC report, she was “hearing voice” when she began attacking her 52-year-old mom. Ray remarked that Mari “died while trying to help her mentally ill daughter.”
In 2016, Shannan Gilbert’s mother Mari, 52, was stabbed 227 times and beat to death with a fire extinguisher—by her daughter, Sarra Gilbert, 27.
Her sister Sherre said, Sarra, had been battling mental illness/schizophrenia for 2 1/2 years.🤔 pic.twitter.com/Cd9IHmFFtH
— Smitty (@SmithJulie25324) April 6, 2025
Sarra was ultimately found guilty of second-degree murder and was handed a 25 years to life in prison sentence. Sherre, one of the last of the Gilbert sisters, shared a heart-wrenching message on Facebook following her mother’s death.
“So, as a lot of you may know. My mother passed away yesterday. She was murdered by my sister, Sarra, who was battling a mental illness for 1/2 years,” she wrote, as reported by TV Insider. She noted that she and her other sister, Stevie, were “devastated beyond words” by Mari’s tragic fate as she was the “backbone of the family.”
Despite her passing, her spirit continues to motivate the bereaved families of other Gilgo victims. In the Netflix series Gone Girls: The Long Island Serial Killer, reporter Robert Kolker noted that had Mari been alive, she would still be fighting for justice.
Today we remember Mari Gilbert.
Mari lived her life on her terms, she was fierce, tireless, obviously relentless and is also missed deeply….. Mari loved her daughters, fiercely, tirelessly and relentlessly.
Mari remained a sheer force of nature that leveraged love,… pic.twitter.com/rRZpRGOfmT
— Catch_LISK (@Catch_LISK) July 23, 2024
“She would not be convinced that Shannan’s death was disconnected from the others,” he said. Despite his client’s tragic end, attorney John Ray continues to be vocal about Heuerman’s potential role in Shannan’s disappearance and death. “There’s so much existing evidence that has existed for years that’s been ignored by police – willfully ignored.”
“There’s no reason to continue that willful behavior, so if it does continue, that if this part of the investigation continues to be ignored, then I know problems still exist in the police,” Ray told the U.S. Sun in 2023.
Sarra was suffering from Schizophrenia for last 1/2 years before she killed her mother, according to her sister.
