Mari Gilbert born on June 22, 1964 to John W. Cox Sr. and JuneRose C. Gran in in Lancaster, Pennsylvania. Mari’s father John W. Cox Sr was a brick-maker who drank hard on the weekends. Her mother June Rose was a woman of faith, changing churches constantly.

She married Floyd Gilbert and had three children with him. Floyd suffered from schizophrenia and was a cocaine addicted.

1985, Mari left her husband and relocated with their three daughters to Rockland County, upstate New York , they briefly stayed with Mari’s Mother JuneRose. At the time, Shannan was five, Sherre was four, and Sarra was three.

In 1987 Mari and her kids and relocated to Ellenville, New York. Mari struggled to support her kids. Mari met David Smith, and they had a daughter, Stevie, in 1992. However, the relationship became violent.

In 1993, When Shannan Gilbert was seven years old she was placed under the care of her foster mother, Dyan Haslam, after JuneRose called the police to report David’s Smith abuse. David was arrested for domestic violence, and her children spent nearly two years in foster care. The youngest girls, Stevie and Sherre, would be eventually be reunited with Mari, but Shannan and her sister Sarra would be raised in foster homes.

in 1998 while in Foster Care, Shannan had been diagnosed with bipolar disorder but had stopped taking her medication due to side effects that caused her to shake.

Mari Gilbert held various jobs over the years, including roles as a retail manager, teaching assistant, and Walmart employee, all while dealing with personal challenges. She met Richard Burner, who moved in with her and the kids.

in 2000, When Shannan was 14, she briefly returned home. It was later discovered that Burner had SA the children. Mari reported him to the police, leading to his arrest and charges of assault. Following this incident, Shannan was removed from their home once more and spent her childhood in foster care, separated from her siblings—Sheree, Sarra, and half-sister Stevie.

2001 While in foster care, Shannan went to New Paltz Central High School, where   She stopped taking her meds in high school because it made her feel sick. .

2003 Shannan graduated early from New Paltz Central High School. After graduating, she worked at various places, including a hotel, an Applebee’s, and a senior center. By 2007, she had relocated to New Jersey with her boyfriend and started working with an escort agency.

The extra income from her work allowed Shannan to move into her own apartment for the first time, in Jersey City, and she was nearing completion of a series of online college courses that might have helped her to leave escorting behind. Shannan enjoyed visiting her family, treating her sisters to shopping sprees, and showering her nieces and nephews with gifts.

Mari, who worked at Walmart, was aware of how Shannan was earning her money and sought to address it with her daughter. “I tried to tell her, ‘Don’t do it. Stop. Move back in with me,’” Mari recalls. But Shannan was adamant. “Mom,” she would reply, “I hardly have to do anything, and I get thousands of dollars.”

On May 31, 2010 The day before Shannan went missing, Mari had a conversation with her daughter. Shannan was planning a visit to Ellenville, New York, to celebrate both Mother’s Day and Mari’s birthday. During their chat, Shannan mentioned that she needed to earn some money to buy her mom a gift. It was their last conversation.

Mari Gilbert made national headlines because of her unrelenting efforts to find the killer of another daughter, Shannan Gilbert, 24, who vanished on Long Island in 2010. The search for Shannan Gilbert led police to discover 10 sets of human remains and touched off a search for a Long Island serial killer, a case that remains unsolved.

Shannan’s body was found on December 13, 2011, alongside the remains of four other women, all known to be online escorts. These four bodies were wrapped in burlap and placed approximately 500 feet apart on Gilgo Beach, prompting police to suspect the involvement of a serial killer later known as the Long Island Serial Killer.

Mari has developed a theory about what happened the night Shannan disappeared, implicating Joseph Brewer, Michael Pak, and possibly a man named Peter Hackett. Hackett is a neighbor of Brewer’s in Oak Beach. The day after Shannan went missing, Mari received a phone call from someone identifying himself as Hackett. The caller claimed to run a home for troubled girls where Shannan had been staying and said she had left unexpectedly. He asked Mari if she knew Shannan’s whereabouts. It was the first time Mari learned that Shannan was missing.

Mari believed that Brewer often brought girls to Oak Beach for parties, with Hackett being aware of these gatherings. She also suspected that Pak may have driven girls to other parties in the area. Even if Brewer, Hackett, or Pak were not directly involved in the deaths of the four confirmed victims, or if they do not know who the perpetrator is, Mari thought they have been less than forthcoming about the murders and Shannan’s disappearance. She believed that if they were more cooperative, they could have provided useful information. The police have consistently stated that Hackett, like Brewer and Pak, is not a suspect in the case.

In May 2012, the Suffolk County medical examiner declared Shannan’s manner of death as “undetermined.” Despite this, Mari was adamant that her daughter had been murdered. She enlisted attorney John Ray to secure access to the 911 tape in hopes of uncovering clues about what happened to Shannan that night.

Additionally, the family commissioned a forensic pathologist to perform an independent autopsy on Shannan’s remains. The autopsy revealed signs consistent with homicidal strangulation, including the absence of a small bone in her throat, which might have been fractured during the murder.

In 2013, a Change.org petition was launched demanding the release of Shannan’s 911 calls. “This is my daughter, and I will NOT stop fighting until justice is done for her!!!!” Mari wrote in the comments of the petition.

In January 2014, Mari and Sherre visited Sarra at her house. Sarra announced that they both were demons and tried to attack Mari before the police came and hospitalized Sarra at Orange Regional Medical Center.

in February, 2014, and again in July, 2014 she was hospitalized again after she’d become convinced that her son was a demon. Sarra spent a summer at that hospital before being transferred to Rockland Psychiatric Center, where she stayed until December 2014.

2015 Mari got engaged to Elroy J. Shulterbrandt

In 2015, Sarra was Diagnosed with paranoid schizophrenia and compelled by a court order, to began receiving a long-acting injectable antipsychotic medication Haldol Decanoate. Sarra was doing much better but by the end of 2015 shs started using illegal drugs, mostly pot but also ecstasy

On Feb. 19, 2016, Sarra drowned her puppy in a bathtub in front of her son because she thought it was the rapper Eminem and it wanted to harm her. Mari Gilbert reported Sarra to the police and Sarra was sent St. Mary’s Hospital by a police, but she was so combative that the police took her to Mid-Hudson Forensic Psychiatric Center, a law-enforcement facility. Hayden Srra’s son stayed with Mari.

By March 2016 The state awarded temporary custody of Hayden to Mary.

July, 2016, Sarra overdosed and transported to Albany Medical Center. The drug had brought her body temperature up to 107.1 ̊F, forcing doctors to pack her in ice. Once awake, Sarra was so delirious and combative that the staff induced a coma to prevent her from harming herself. Once Sarra was released from the hospital Mari and Sherre tried visiting Sarra at home, but Sarra wouldn’t open the door. Mari left a cup of coffee for her. Sarra believed it had been poisoned and dumped it in the trash.

On the morning of July 23, 2016, Sarra texted her sister Sherre and told her that she was hearing voices. Then, Sarra called Mari, who rushed to her apartment in Ellenville, New York. She arrived around 10:30 a.m. and sat on the couch next to Sarra.

Unbeknownst to Mari, however, Sarra had concealed a kitchen knife beneath a throw pillow — and she suddenly pulled it out and started stabbing Mari in the chest. Mari tried to fight back, but Sarra sat on top of her and continued her violent assault. She plunged the knife into her so viciously that the blade bent and the tip broke off.

After stabbing Mari hundreds of times, Sarra grabbed a fire extinguisher and bashed her mother in the head and face before spraying foam from the device in her mouth. After she was sure Mari was dead, Sarra smoked a cigarette and listened to music.

When Sherre couldn’t get in touch with Mari later that morning, she called the police and asked them to carry out a welfare check at Sarra’s apartment.

July 23, 2016, 1:45 p.m police officers performing a welfare check at the home of 27-year-old Sarra Gilbert found her mother, Mari Gilbert, lying in a pool of blood and riddled with stab wounds. As soon as the officers walked into the apartment, Sarra told them, “I am under arrest.”

Sarra suffered from paranoid schizophrenia, and voices in her head had been telling her that her mom was dangerous. So, when Mari stopped by to check on her that morning, Sarra attacked her with a kitchen knife and a fire extinguisher.

On the morning of July 23, 2016, Sarra texted her sister Sherre and told her that she was hearing voices. Then, Sarra called Mari, who rushed to her apartment in Ellenville, New York. Mari arrived around 10:30 a.m. and sat on the couch next to Sarra…