The state can use the evidence it gathered from a South Barrington man 16 years ago who has since been charged with murdering his wife because he gave the information voluntarily, a state appeals court found last week.The 1st District Appellate Court on Tuesday reversed the decision of Cook County Associate Judge James N. Karahalios to suppress the statements and evidence the police collected from Frank Buschauer, who called the police saying he found his wife dead in their bathtub on Feb. 28, 2000.Buschauer was charged in …