TYNGSBOROUGH, Mass. — Authorities in Massachusetts say a missing woman’s remains have been tentatively located more than a year after her disappearance, following a tip that led investigators to a suspect’s home.
The Middlesex County District Attorney’s Office announced that 40-year-old Shawn Sullivan has been arrested and charged with murder, assault and battery with a dangerous weapon causing serious bodily injury, and improper disposal of human remains.
During a press briefing, District Attorney Marian Ryan and Tyngsborough Police Chief Shaun Woods explained that the case gained momentum after law enforcement in Nashua, New Hampshire, received information about a possible homicide. A caller reported that Sullivan allegedly admitted to shooting and killing a woman identified as “Jill” at his Tyngsborough residence around January 2025 and claimed he had buried her beneath his garage floor.
Investigators reviewed missing persons records and found that Jill Kloppenburg had been reported missing to Tewksbury authorities in February 2025. Officials determined that Sullivan was acquainted with Kloppenburg and that she had been at his home around the time she disappeared.
On March 15, detectives from the Tyngsborough Police Department, Tewksbury Police Department, and Massachusetts State Police executed a search warrant at Sullivan’s Audrey Avenue residence. Inside the garage, officers noticed what appeared to be a large, patched section of flooring.
Ground-penetrating radar indicated that part of the garage floor had been cut and repaired. After removing the concrete, investigators discovered a bag containing human remains.
Authorities have not yet officially confirmed the identity of the remains. The Office of the Chief Medical Examiner is conducting further examination to establish identification and determine the cause and manner of death.
Officials emphasized that the investigation is ongoing and urged anyone with relevant information to contact Massachusetts State Police.
