A shocking discovery in a quiet suburban neighborhood in Tyngsborough, Massachusetts, has left residents reeling: human remains believed to be those of a long-missing woman were unearthed buried beneath the concrete floor of a local man’s garage, right under the noses of unsuspecting neighbors who lived mere feet away for over a year.

Shawn Sullivan, 40, of Tyngsborough, was arrested and charged with murder, assault and battery with a dangerous weapon causing serious bodily injury, and improper disposal of human remains following the grim find on March 16, 2026. Middlesex County District Attorney Marian Ryan announced the charges at a press conference, detailing how the case unfolded after a tip from New Hampshire led authorities straight to Sullivan’s family home on Audrey Avenue, about 28 miles north of Boston.

The breakthrough began on March 10, 2026, when a friend of Sullivan contacted Nashua, New Hampshire police to report a possible homicide. According to authorities, the tipster claimed Sullivan had confessed to shooting and killing a woman he referred to as “Jill” around January 2025, then burying her body beneath the floor of his two-car garage. The confession aligned chillingly with the timeline of Jillian Kloppenburg, a 47-year-old woman from nearby Lowell who vanished more than 14 months earlier.

Kloppenburg was last seen leaving her home in Lowell on January 2, 2025. Her phone showed activity as late as January 14, 2025, but friends reported no physical sightings since August 2024 and no phone contact after November 2024. She was officially reported missing to Tewksbury Police in February 2025, with her case later listed in the FBI’s missing persons database.

Investigators, armed with a search warrant, arrived at Sullivan’s residence and employed ground-penetrating radar to scan the garage. The technology detected an anomaly beneath a large, recently patched section of the concrete floor. After carefully breaking through the surface, officers recovered human remains wrapped in a plastic bag from a shallow grave-like burial site.

While formal identification awaits DNA testing and an autopsy, officials expressed strong confidence that the remains belong to Kloppenburg. Her uncle, Steven Kloppenburg, shared on Facebook that investigators had informed the family they were “100% positive” it was her, though official confirmation is pending. “She’s been missing for 14 months and has probably been out there for the whole time,” he wrote, as reported by CBS News.

The revelation has sent shockwaves through the close-knit community. Neighbors, who had gone about their daily lives—perhaps waving hello or chatting over fences—were horrified to learn that a suspected crime scene had existed undetected in their midst for more than a year. The idea that human remains lay buried just below the surface of an ordinary garage, hidden in plain sight, has left many feeling unnerved and betrayed by the proximity of such horror.

Sullivan, described as a friend of Kloppenburg who had hosted her in his home and was allegedly with her around the time of her disappearance, now faces life-altering charges. He is expected to be arraigned in Lowell District Court.

For Kloppenburg’s loved ones, the discovery marks a painful but necessary step toward closure. A longtime friend, Ann Matlosz, spoke emotionally to Boston 25 News about her devastation upon learning of the alleged circumstances. “You don’t throw her away,” she said of the suspect. “You don’t throw anybody away. They don’t deserve that… Like why? Like how little of a man are you?”

The family told media outlets they can now shift their focus to seeking justice and beginning the long process of healing after more than a year of uncertainty and anguish.

As the investigation continues, the case serves as a stark reminder of how tragedy can hide behind the facade of everyday suburban life, only to emerge in the most horrifying ways. Authorities hope that forensic confirmation will soon provide final answers and allow Kloppenburg’s loved ones to lay her to rest with dignity.