THE mom of the Gilgo Beach victim whose death broke the Long Island serial 𝓀𝒾𝓁𝓁ing case wide open was murdered before she could ever see justice.

Shannan Gilbert’s mother Mari was heartlessly stabbed 227 times by her surviving daughter years before investigators arrested suspect Rex Heuermann.

Mari Gilbert, seen with her lawyer John Ray in 2011, was the mom of one of the women whose remains were found on Gilgo BeachCredit: AP

Shannan Gilbert disappeared in May 2010, and her body was found with six others off the ill-fated Long Island, New York, shoresCredit: Facebook

Disgraced architect Rex Heuermann has been accused of murdering seven women, but he hasn’t been linked to Shannan’s deathCredit: Getty

Mari, seen in 2016 with her daughters and Ray, was murdered by Sarra Gilbert (seen back center)Credit: AP

Mari was a familiar face to Long Island, New York, natives as she was one of the first people to publicly suggest that a serial 𝓀𝒾𝓁𝓁er was on the loose when Shannan disappeared in May 2010.

Her disappearance came just months after the remains of four women, known as the Gilgo Four, were uncovered on the ill-fated shores.

The mom appeared on local television many times to demand justice for her daughter Shannan, who ran away from a client she met on Craigslist for 𝓈ℯ𝓍 work and was never seen again.

While searching for Shannan, investigators found not only her body but five other sets of remains off the ill-fated shores, bringing the total number of bodies found to 10.

Because of Shannan, an urgent search for the Long Island Serial Killer began.

It’s unclear how Shannan died, and investigators don’t suspect that she was murdered.

However, seven of the other victims have been linked to Heuermann – a disgraced architect who lived on Long Island and ran a private firm in Manhattan.

But Mari never got to see glimmers of justice for those women, as the 52-year-old mom was murdered by her schizophrenic daughter, Sarra.

On July 23, 2016, Sarra came into Mari’s Cats𝓀𝒾𝓁𝓁s apartment, stabbed her mother over 200 times, and beat her with a fire extinguisher.

The daughter was found guilty of second-degree murder and was sentenced to 25 years to life in prison.

According to John Ray, an attorney who to this day represents Gilto Beach victims, Sarra was “hearing voices” when she lashed out at her mom.

He claimed that Sarra, who lived in a separate adjoining apartment, came over because she was hallucinating, WNBC reported in 2017.

The lawyer said the mom “died while trying to help her mentally ill daughter.”

Sarra was reportedly having a hallucination when she murdered her motherCredit: Ellenvill Police Department’BACKBONE OF THE FAMILY’

Sherre Gilbert, a surviving daughter of Mari, shared a heartwrenching message following her mother’s death.

In a Facebook post, she wrote, “So as a lot of you may know, my mother passed away yesterday,” TV Insider reported.

“She was murdered by my sister, Sarra who was battling a mental illness for 2 1/2 years.”

An emotional Sherre said that she and her sister Stevie were “devastated beyond words” after hearing the tragic news.

She described Mari as the “backbone of the family.”

In the Netflix docuseries Gone Girls: The Long Island Serial Killer, which premiered in March, reporter Robert Kolker suggested that Mari would still be fighting to this day if she were alive.

“She would not be convinced that Shannan’s death was disconnected from the others,” he said in the series.

Heuermann has been accused of murdering seven womenCredit: AP

Ten bodies have been found on Gilgo BeachCredit: AP

Shannan, who was a 𝓈ℯ𝓍 worker, was fleeing a client when she disappearedCredit: Family PhotoCASE CONTINUES

Heuermann has been accused of murdering the Gilgo Four, Megan Waterman, Melissa Barthelemy, Amber Lynn Costello, and Maureen Brainard-Barnes, along with Jessica Taylor, Sandra Costilla, and Valerie Mack.

Though Mari met a tragic end in 2017, her attorney John Ray continues to voice his belief that the Long Island serial 𝓀𝒾𝓁𝓁er murdered Shannan.

Cops believe that she may have died of natural causes, but Ray claims there’s overwhelming evidence that she was 𝓀𝒾𝓁𝓁ed.

“There’s so much existing evidence that has existed for years that’s been ignored by police – willfully ignored,” Ray told The U.S. Sun in 2023.

“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.”

Shannan’s story is being retold in the Peacock docuseries The Gilgo Beach Killer: House of Secrets, which is now streaming.

No trial date has been set for Heuermann. His next court appearance is scheduled for June 17.

Mari was a familiar face in Long Island for her constant interviewsCredit: AP