Sherre Gilbert is the older sister of Shannan Gilbert, the 23-year-old woman whose 2010 disappearance from Oak Beach on Long Island led police to discover the remains that became the Gilgo Beach serial murder case. After her mother Mari Gilbert was killed in 2016, Sherre became the family’s public voice, pressing Suffolk County authorities to treat Shannan’s death as a homicide rather than an accident and carrying forward a civil lawsuit against an Oak Beach doctor the family blames for what happened that night.
Why Her Sister’s Case Still Matters
On May 1, 2010, Shannan Gilbert traveled from New Jersey to meet a client, Joseph Brewer, at his home in the gated Oak Beach community. During the visit she placed a 911 call telling the operator, “There’s somebody after me” and “They’re trying to kill me.”1ABC7 New York. Gilgo Beach Murders 911 Calls Released by Suffolk County Police She ran from the house, banged on neighbors’ doors asking for help, and vanished before police arrived. Brewer and her driver Michael Pak were later cleared of criminal involvement.2ABC News. 911 Calls Released in Connection With Woman Whose Disappearance Led to Gilgo Beach Investigation
The search for Shannan became the accidental trigger for a much larger case. On December 11, 2010, a police K9 team looking for her along Ocean Parkway found the remains of Melissa Barthelemy. Within days, three more sets of remains were discovered nearby — Maureen Brainard-Barnes, Megan Waterman, and Amber Costello — the women who became known as the Gilgo Four.36ABC. Gilgo Beach Serial Killings Timeline Shannan’s own skeletal remains were not found until December 2011, about eight miles away in a marsh.4CBS News. Long Island Serial Killings Investigation Timeline
The Dispute Sherre Gilbert Is Fighting
From the start, the Gilbert family has rejected the official theory of how Shannan died. The Suffolk County Medical Examiner classified her cause and manner of death as “undetermined,” pointing to the severe decomposition of a body left eighteen months in a saltwater marsh.5CBS News New York. Shannan Gilbert New Autopsy Suffolk County police have nevertheless maintained the death was not a homicide, suggesting Shannan ran into the marsh in a state of drug-induced panic and drowned. An FBI Behavioral Analysis Unit review found her death was “most likely an accident” and “not consistent with homicide.”2ABC News. 911 Calls Released in Connection With Woman Whose Disappearance Led to Gilgo Beach Investigation
The family commissioned its own autopsy from Dr. Michael Baden, the former chief medical examiner of New York City. Baden reported that the hyoid bone in Shannan’s neck was broken with a hole through its center, injuries he called “consistent with homicidal strangulation.” He also noted that the larynx was missing and that the two greater horns of the hyoid bone — structures often fractured in manual strangulation — were absent.6CNN. Shannan Gilbert Case He said he found “no evidence that she died of a natural disease, of a drug overdose or of drowning.”5CBS News New York. Shannan Gilbert New Autopsy
That contradiction is the ground Sherre has stood on for more than a decade.
Her Public Advocacy
After the Suffolk County Police Department reaffirmed in May 2022 that it did not believe Shannan was a victim of the Gilgo Beach serial killer, Sherre and family attorney John Ray held a press conference calling on the New York State Attorney General to appoint a monitor to review the case.7Oxygen. Shannan Gilbert Sister and Attorney Speak Out on 911 Calls Ray asked that current homicide detectives be removed and that “fresh eyes” examine the investigation, accusing the department of having “covered that up for all these years.”8CBS News New York. Shannan Gilbert’s Family Speaks Out
Sherre has consistently used the released 911 recordings to argue that her sister was coherent and terrified rather than hallucinating. “She ran for her life. She was in fear,” she said in 2022. “Why would she then run into the marsh?”7Oxygen. Shannan Gilbert Sister and Attorney Speak Out on 911 Calls She has stated publicly that she believes someone found Shannan that night, drugged her, and disposed of her body.9ABC7 New York. Shannan Gilbert’s Sister Demands Independent Investigation
In June 2024, Sherre broke publicly with Ray after he held a press conference focused on Rex Heuermann’s daughter rather than Shannan’s case. On X, she wrote: “I do not agree with anything John Ray is doing. This is disrespectful and I had no prior knowledge to this ‘press conference’ or the ‘evidence’ he was presenting today. He should’ve been there to discuss Shannan’s case period!”10Long Island Press. John Ray Blasted Over Heuermann Family Press Conference
The Lawsuit Against Dr. Charles Peter Hackett
The central piece of the family’s legal fight is a civil case against Dr. Charles Peter Hackett, an osteopathic physician who lived in Oak Beach when Shannan disappeared. Mari Gilbert filed the suit in Suffolk County Supreme Court in November 2012, alleging that Hackett ran a home for “wayward girls” out of his residence, that he “coerced Gilbert into his home” the night of May 1, 2010, administered narcotic drugs to her, and then released her in a “helpless state” that led to her death.11Newsday. Shannan Gilbert’s Family Files Wrongful Death Suit
The complaint rests partly on phone records and neighbor statements. Court filings allege Hackett called Mari Gilbert’s cellphone on May 3 and May 6, 2010, and called Sherre’s phone on May 6. In a 2013 affidavit, Mari recounted that a man identifying himself as Dr. Hackett told her he had tried to help Shannan and had treated her at his home, but that she left with her driver. An Oak Beach neighbor, Joseph C. Scalise, provided a statement saying he overheard Hackett tell his wife that “his intention was to help SG — not to kill her.”12New York Courts. Estate of Gilbert v Hackett
Hackett has denied every allegation under oath. He maintains he never met Shannan Gilbert, never had her inside his home, and never administered any medical treatment to her, and his wife and adult children submitted supporting affidavits.12New York Courts. Estate of Gilbert v Hackett Police questioned him during the criminal investigation and cleared him.11Newsday. Shannan Gilbert’s Family Files Wrongful Death Suit
The case has moved slowly. Several claims, including wrongful death and intentional tort causes of action, were dismissed in December 2013 as time-barred. The surviving claims allege medical malpractice, negligence, gross negligence, breach of fiduciary duty, and fraudulent inducement. In October 2018, the court granted the Gilbert estate’s motion to enforce subpoenas against the Suffolk County Police Department for 911 recordings and transcripts from the night of the disappearance.13FindLaw. Estate of Gilbert v Hackett After Mari’s death, Sherre took over as administratrix of both Shannan’s and Mari’s estates and continued the litigation. In November 2025, a judge ruled that the estate could move forward, finding sufficient evidence on emotional distress claims to keep the case alive.14News 12 Long Island. Judge Rules Shannan Gilbert’s Estate Can Move Ahead With Lawsuit Against Dr. Peter Hackett
How She Became the Family’s Last Voice
On July 23, 2016, Mari Gilbert was killed at her Catskills home by her daughter Sarra Gilbert, Sherre’s sister. Prosecutors said Sarra, who suffered from schizophrenia, stabbed her mother 227 times with a kitchen knife, bludgeoned her with a fire extinguisher, and sprayed the extinguisher’s foam into her mouth. When police arrived, Sarra was sitting beside the body and told them, “I killed my mom.”15CNN. Mari Gilbert, Mother of Shannan Gilbert Sherre was the family member who grew worried when Mari did not respond that day and called police.16ABC7 New York. Shannan Gilbert’s Mother Stabbed to Death
Trial evidence showed Sarra had experienced hallucinations in which voices called her mother “the devil.” Family tensions had sharpened after an earlier incident in which Sarra drowned a puppy in front of her son, prompting Mari to take custody of the child in February 2016.15CNN. Mari Gilbert, Mother of Shannan Gilbert An Ulster County jury rejected an insanity defense in April 2017 and convicted Sarra of second-degree murder; she was sentenced to 25 years to life.17NBC New York. Sarra Gilbert Found Guilty of Murdering Mother Mari Gilbert In November 2021, the Appellate Division’s Third Department unanimously upheld the verdict, citing Sarra’s own trial testimony that her “intention was to kill my mom” and her admission to police that she knew stabbing was wrong.18Times Union. Appeals Court Rejects Insanity Defense in Vicious Killing
With Mari gone and Sarra in prison, Sherre was left as the family’s spokesperson. Journalist Robert Kolker, whose book Lost Girls chronicled the Gilgo Beach victims and their families, has written that by the end of her life Mari had “mended fences” with Sherre. John Ray said of Mari: “By any human standard, she redeemed herself in the end.”19The Cut. The True Crime Tragedy Behind Lost Girls
Where the Case Stands Now
In July 2023, Massapequa Park architect Rex Heuermann was arrested on charges of murdering several of the women whose remains were found along Ocean Parkway. He has since pleaded guilty to the murders of eight women, including the original Gilgo Four and other victims identified later.4CBS News. Long Island Serial Killings Investigation Timeline He has not been charged in connection with Shannan Gilbert’s death, and authorities continue to say the two matters are unrelated. Kolker has called Shannan’s case “the case’s first and last great unsolved mystery.”20New York Times. Shannan Gilbert and the Gilgo Beach Murders In October 2023, Ray presented two sworn affidavits to then-Suffolk Police Commissioner Rodney Harrison that he said linked Heuermann to both Shannan Gilbert and victim Karen Vergata; no charges followed.10Long Island Press. John Ray Blasted Over Heuermann Family Press Conference
As of late 2025, Shannan Gilbert’s official cause of death remains undetermined, the civil case against Dr. Hackett is still moving through the courts, and Sherre Gilbert continues to press, as her mother did before her, for a different answer than the one Suffolk County has given.