Massachusetts man charged with murder after human remains found that may be missing woman

TYNGSBOROUGH – Middlesex District Attorney Marian Ryan and Tyngsborough Chief of Police Shaun Woods have confirmed through a press release that 40-year-old Shawn Sullivan of Tyngsborough has been charged with murder, assault and battery with a dangerous weapon causing serious bodily injury and improper disposal of human remains in connection with the alleged shooting of a victim whose identity has not yet been confirmed and burying them under the floor of the garage of the home where he lived.

On Tuesday, the Nashua, NH, Police Department received a call regarding information about a possible homicide. The reporting party told police that his friend, a man named Shawn Sullivan, had allegedly told him that he had killed a woman named “Jill” at this home in or around January 2025, and that he had allegedly shot her and buried her under the floor in the garage of the Audrey Avenue home in Tyngsborough where he was living.

Nashua Police were able to identify, through a missing persons database, that there was a woman who had been reported missing to Tewksbury Police in February 2025 named Jill Kloppenburg. Based on the subsequent investigation police learned that the defendant allegedly knew Kloppenburg, that she had been in his home and that he had allegedly been with her around the time of her disappearance.

On Sunday, detectives from the Tyngsborough Police Department, Tewksbury Police Department, and Massachusetts State Police executed a search warrant on the Audrey Avenue home and observed what appeared to be a large, patched area in the garage. Using Ground Penetrating Radar technology investigators were able to scan the full garage floor and confirmed an area that appeared to be cut and patched.

Investigators subsequently were able to cut through the floor of the garage and recovered a bag containing human remains.

Shawn Sullivan was arrested by Tyngsborough Police yesterday and will be arraigned tomorrow in Lowell District Court.

This matter has been referred to the Office of the Chief Medical Examiner who will attempt to determine the cause and manner of death and positive identity of the victim.

This is still a very active investigation, and authorities are encouraging anyone with any information about Kloppenburg to immediately contact Massachusetts State Police at 781-897-8300.

Watch the press conference here: https://youtu.be/sISZ4NobNZw?si=AIv-5RrTqYltDqGQ