Man allegedly confesses to killing missing woman, burying her under garage: prosecutors

TYNGSBOROUGH, Mass. — A Massachusetts man was charged with murder after human remains were found buried beneath the garage floor of his home, according to prosecutors.

The Middlesex District Attorney’s Office on Monday said 40-year-old Shawn Sullivan was accused in connection with the death of a woman believed to be Jill Kloppenburg, 47, who was reported missing more than a year ago.

Middlesex District Attorney Marian Ryan said the investigation began after authorities received a tip that Sullivan had allegedly told a friend he murdered a woman at his home.

“Shawn (told someone) he allegedly killed a woman named Jill at his home in or around January 2025,” Ryan said during a news conference. “Shawn further claimed that he had shot her and then buried her under the floor in a garage in the … Tyngsborough home where he was living.”

Ryan said investigators on Sunday executed a search warrant at the property, where they identified a suspicious, patched section of the garage floor.

Using ground-penetrating radar, she said investigators found what appeared to be buried material beneath the concrete. After cutting into the floor, they recovered a plastic bag containing human remains.

While the remains have not yet been formally identified through DNA testing, investigators believe they belong to Kloppenburg, who was reported missing in February 2025.

Ryan said investigators learned the last time there was communication through Kloppenburg’s cell phone was on Jan. 14, 20205.

“Police were able to learn that Ms. Kloppenburg was someone known to Mr. Sullivan, that she had been in his home, and that he had allegedly been with her around the time of her disappearance,” Ryan said.

Tyngsborough Chief of Police Shaun Woods

In addition to murder, Sullivan was also charged with assault and battery with a dangerous weapon, causing serious bodily injury, and improper disposal of human remains.

Authorities said the case remains under investigation as the medical examiner works to determine official cause and manner of death of the remains.