In November 2012, a police officer named Tom Decker was shot and killed in Cold Spring, Minn., after getting out of his car to check on a man who lived above a bar. The man was quickly arrested and held in the Stearns County jail. He was interrogated but then released without charges. The state crime bureau later ruled him out as a suspect. Investigators turned their focus to another man, Eric Thomes, who hanged himself before he could be charged with the crime. Nearly four years after the murder, Sheriff John Sanner has refused to close the case “because we’re still hopeful that new information will come in,” he said.