TLDR
Massachusetts prosecutors charged Shawn Sullivan with murder after a friend told police he confessed to killing a woman. Investigators used databases and ground-penetrating radar, then uncovered a body beneath a Tyngsborough garage, believed to be missing Lowell woman Jill Kloppenburg.
When a 43-year-old Lowell woman disappeared in January 2025, friends reported her missing and waited for answers that did not come. More than a year later, that case has shifted into a homicide prosecution centered on a garage floor in nearby Tyngsborough.
Investigators now believe the remains recovered from beneath that garage belong to Jill Kloppenburg, although the body has not been formally identified. Prosecutors say the discovery followed a tip from a friend of 40-year-old Shawn Sullivan, who is now charged with murder and related offenses in Middlesex County.
Tip From Friend Spurs Search
According to Middlesex County District Attorney Marian Ryan, a friend of Sullivan contacted the Nashua Police Department in New Hampshire on March 10th, 2026, reporting that Sullivan had admitted to killing a woman named Jill around January 2025. That disclosure prompted investigators to review missing person databases and prior reports.
Authorities determined that Sullivan and Kloppenburg knew each other and focused on a home on Audrey Avenue in Tyngsborough where he had previously lived. Ryan said investigators used ground-penetrating radar on the two-car garage, then excavated a large patched section and uncovered human remains wrapped in plastic.
From Missing Person Report to Homicide Charge
Prosecutors’ accounts describe a lengthy gap between Kloppenburg’s disappearance and the recovery of a body. She was last seen leaving her Broadway home in Lowell on January 2nd, 2025, and was not reported missing until February 26th, 2025, after friends told police they could no longer reach her.
Ryan has said the victim in the case is being referred to as Jane Doe until the medical examiner confirms the identity and determines the cause and manner of death. Along with the murder count, Sullivan faces charges of assault and battery with a dangerous weapon, causing serious bodily injury, and improper disposal of human remains, and he is scheduled for arraignment.
Unresolved Questions on Investigation Timeline
The public record so far leaves key aspects of the investigation timeline unclear. Officials have not detailed what steps investigators took between the February 2025 missing person report and the March 2026 tip that led them to the Tyngsborough property, or whether the garage was previously searched.
Kloppenburg’s uncle wrote on social media that he had been notified about the discovery of remains and expressed grief over what might have been, adding, “There will be a resolution.” Any such resolution will depend on forthcoming court filings and autopsy findings, which are expected to clarify what happened and how authorities built their case.
