The body of a man was recovered from the lake in Wilmette just before 4:15 p.m. Sunday afternoon. Wilmette fire crews and the U.S. Coast guard worked to recover the body.
Police said it appeared the person had been in the water for at least a couple of weeks before a boater spotted the individual about 1 mile offshore.
An autopsy will determine the cause of death.
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Wilmette police said the man's description does not match any missing persons reports in the area.
He was described as having black hair and being about 6-feet tall.
Anyone with information is asked to call the Wilmette Police Department at 847-256-1200.