By CBS 2 Chicago Staff

CHICAGO (CBS) — The murder of a husband and found stabbed to death in their home in the northwest suburbs has stunned a neighborhood. Police believe a woman living with them is responsible.

Algonquin police say there have been several calls to the house where the three lived in the past year. The most recent was Friday, when detectives say the suspect shoved the husband. They believe just hours later, things escalated to murder.

What neighbors knew about 635 Red Coach Lane was it was home to a woman who loved to say “Hi.”

“She smoked so she’d be out there and holler over, ‘Hey Karen, what are you doing?'” a neighbor said.

She was 69-year-old Noreen Gilard, who shared the home with her 73-year-old husband, Leonard.

“She was always nice always happy go lucky, knew most of the neighbors. The neighbors knew her,” said neighbor Margaret Gittings.

So it was strange when friends of the couple had not heard from them in days. They called police to check on the house where officers found the pair dead from stab wounds on Sunday night. Hours later they had a suspect, who was also known to neighbors — 39-year-old Arin Fox.

“She looked like she may have been the girl that lived over there for a while,” a neighbor said.

Police say Fox is a family friend who was living at the home with the Gilards, though they do not know the circumstances or for how long. What officers say they do know is Fox took one of the couple’s cars after the murders sometime over the weekend and drove it more than 14 hours to Littleton, Colorado, where she was arrested. Fox previously lived in Boulder before moving to Illinois.

“I walk every day, so there were times not all the time, but I would see her take a walk around the block or something,” said Gittings.

What may have made Fox turn on the people who took her in is still a mystery.

Fox faces four charges of first degree murder, plus two for battery and one for theft of the car. She is still in custody in Colorado awaiting extradition back to Illinois.