It was the great Houston murder mystery of the nineties. Who shot 46-year-old Doris Angleton, the beautiful, ebullient River Oaks mother of two young daughters and the wife of Robert Angleton, Houston’s top bookmaker? When Doris was found in her home in 1997—she had been shot thirteen times—their friends speculated that the killing had been carried out by one of Angleton’s underworld rivals. But then Angleton’s brother, Roger, was found in Las Vegas with a briefcase containing typewritten notes about the crime and tape recordings of two men plotting a murder. The police charged Robert and Roger with Doris’ murder. Because the couple were splitting up, detectives believed that Robert had feared she would reveal details about his multimillion-dollar operation to a divorce judge. When I wrote about the case in November 1997’s “The Bookmaker’s Wife,” I assumed the brothers’ conviction was a foregone conclusion. But after the article was published, Roger committed suicide in jail, and jurors acquitted Robert at his 1998 murder trial. Now, the U.S. attorney’s office is investigating the 52-year-old on suspicion of tax evasion, money laundering, gambling, and federal murder charges. Prosecutors are so determined to find new evidence that they subpoenaed all the notes of Houston true-crime writer Vanessa Leggett, who has spent four years researching the case. Leggett, who has numerous confidential sources, went to jail in July rather than give up her information. Michael Ramsey, Angleton’s lawyer, says that if a new indictment is issued, it will probably happen before the end of the year.