SPRINGFIELD, Mass. -- Police in Springfield, Massachusetts, had no idea when they arrested a man for kidnapping on Sunday that the story would soon take an even darker turn. Three bodies have now been found in the house where the man was living, and it's now a major crime scene.

On Friday, investigators used ground-penetrating radar to look for more evidence after finding the three bodies in and around the small bungalow, which authorities say is the residence of 40-year-old Stewart Weldon.

This photo provided by the Springfield Police Department shows Stewart Weldon. Springfield Police Department via AP

A police report shows Weldon was arrested on Sunday after a car chase, and the discovery of a female passenger who said she'd been kidnapped and physically abused. An officer wrote that her injuries were "grotesque and violent," including stab wounds to her abdomen, and a possible fractured jaw.

The report says that before being transported to the hospital, the woman told police: "Thank you guys for saving my life, I didn't think I was ever going to get away."

Hampden County District Attorney Anthony Gulluni says additional information later led police to the house.

"We are operating under the assumption that these deaths are suspicious," Gulluni said.

But he wouldn't say whether he has a serial killer on his hands, or provide any details on the genders or ages for the three bodies found.

The Boston Globe reports Weldon was arrested three times in 2017. In October he had a scuffle with police which led to him being outfitted with a GPS tracking device. Earlier this year, police say he cut that ankle bracelet off.