SHOREWOOD (CBS)– The FBI and Illinois State Police searched a southwest suburban forest preserve Monday afternoon — attracting the attention of the sister of the missing Stacy Peterson, although authorities wouldn’t say what they were looking for.

Cassandra Cales arrived at the 400-acre Hammel Woods near Shorewood Monday afternoon after the search was completed, Sun-Times Media is reporting.

She said she had heard about the search, but had not been called by authorities. Cales left a few minutes later without speaking to investigators.

Stacy Peterson, the fourth wife of convicted cop Drew Peterson, has been missing since Oct. 28, 2007, shortly after telling the then-Bolingbrook police sergeant she wanted a divorce. He has been named by authorities as a suspect in Stacy’s unsolved disappearance.

He was convicted in September of killing his third wife, Kathleen Savio, and is awaiting sentencing.

ISP Capt. Michael Cooke confirmed detectives had searched the woods as part of an ongoing investigation, but would not comment further. ISP spokeswoman Monique Bond said nothing unusual was found and investigators aren’t expected to return Tuesday.

The FBI helped in the search, which ended by 4 p.m. An FBI spokeswoman would only say it was “in connection with an ongoing criminal matter.”

Will County Forest Preserve police referred questions to state police.

A Plainfield Fire Department canine vehicle was also at the scene.

Joliet police said the search had no connection to their efforts to find Linda Barr Fellenbaum, who has been missing since Oct. 21. Friends and family searched for the missing 32-year-old mother of three on Sunday.

The Will County Coroner’s office said it had not been called out or requested to stand by at the preserve.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2012. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

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