NORTH SALEM, N.Y. (CBSNewYork) — The murder investigation continues into the death of a wealthy New York socialite.

Lois Colley, 83, was found bludgeoned to death Monday inside her sprawling hilltop estate known as Windswept Farms on Titicus Road in North Salem.

“She was found in the laundry room, which is just inside the garage, and she was lying on the floor,” said New York State Police Lt. Paul DeQuarto.

She was last heard from around 3 p.m. Monday, and she was dead by 5:20 p.m.

There was no sign of forced entry.

“It’s very sad, very sad. I don’t know who could do that to an 83-year-old woman,” said Sandy Brugger, who works in the area.

Police said a handheld fire extinguisher is missing from the estate, and investigators are considering that the possible murder weapon in the case, CBS2’s Janelle Burrell reported.

“We’re asking the public that if they come across a fire extinguisher on their property, on the side of the road that we would definitely would like to know about,” DeQuarto said, WCBS 880’s Sean Adams reported.

Police spent much of Tuesday searching by air and on the ground around the 300-acre estate where Colley lived with her husband, Eugene Colley, who made his fortune owning about 100 McDonald’s franchises across the country.

State police were also in Croton Falls, speaking with employees at the Colley Group’s business headquarters, CBS2’s Lou Young reported.

Investigators have no suspect, no weapon and no motive in the case.

“Who does something like this? Who goes to a house and there was no robbery, and there was nothing missing, no money missing, nothing else. And they murder this poor woman,” said Mahopac resident Nick Altamare. “Sounds like somebody planned it, without a doubt.”

Police are questioning everybody who regularly came in contact with the victim. Her husband and sons have been ruled out as suspects, CBS2 reported.

State police said they’re checking into local burglaries and attempted break-ins, including a pattern in nearby Ridgefield, Connecticut. But a source told CBS2 it doesn’t look like there is a connection with any other cases.

“She was a very, very nice lady. Every time you see her, she gives you a kiss,” said North Salem Town Supervisor Warren Lucas. “It’s just beyond unfortunate.”

The Colley family is well known in New York, moving in some of the same social circles as the Kennedys, Young reported.

Colley’s eldest son, Bruce Colley, made headlines briefly in 2003 as the “other man” in Gov. Andrew Cuomo’s divorce from Kerry Kennedy.

State police also asked area residents to remain vigilant for suspicious activity.