CAN TEXAS MULTIMILLIONAIRE HERB VEST PROVE A GAINESVILLE, TEXAS POLICE OFFICER WAS RESPONSIBLE FOR HIS FATHER'S DEATH ALMOST 60 YEARS AGO? -- A "48 HOURS MYSTERY" SATURDAY, FEB. 12

Texas multimillionaire Herb Vest is searching for who killed his father almost 60 years ago. Twenty-five-year-old Harold "Buddy" Vest was found hanging in his cabinet shop in June 1946 in the small town of Gainesville, Texas, and although the police ruled his death a suicide at the time, Herb always thought there was more to it. Now, he has launched his own investigation � hiring a team of experts to search for the truth. Vest receives a mysterious letter that claims that someone who was on the Gainesville police force was responsible for Buddy's death. Will Vest find his father's supposed killer? Correspondent Harold Dow reports for 48 HOURS MYSTERY: "Postmarked for Murder," to be broadcast Saturday, Feb. 12 (10:00-11:00 PM, ET/PT) on the CBS Television Network.

Buddy Vest had just returned from World War II, was happily married, the father of a two-year-old and trying to make it as a carpenter when he was discovered hanging in his cabinet shop. The death was ruled a suicide, though a suicide note was never found. Immediately following Buddy's death, his wife, Ruth, left Gainesville with her young son and never looked back.

Ruth told her son that his father died of unknown causes, but when young Herb turned 11, he found some old family letters and discovered that his father's death was a suicide � something he never told his mother he knew. Not until five or six years ago did Herb's mother finally share with her son the truth about his father's death.

Herb Vest's ad in the newspaper asking for information offered a reward that is now up to $25,000. After placing the ad, Vest receives a mysterious letter from an "M. Smith" that claims Buddy Vest did not commit suicide, and in fact points to an unidentified former Gainesville police officer and his friends as the ones responsible for Buddy's death. Herb's team of investigators have been examining the mysterious letter they received and searching for the author, "M. Smith." The letter was rich in detail and told how "M. Smith" arrived at Buddy's shop the night of his death. "M. Smith" talked about a man she had been dating -- a married cop she calls "Jim," who showed up at Buddy's shop with two friends. "M. Smith" describes a horrifying scene and says Buddy was tortured and hanged to make it look like a suicide. Fifty-eight years later, the Cook County Justice of the Peace in Texas says this case was a police cover-up, has ruled it a homicide and is trying to find "M. Smith" because only then will the authorities be able to find the killers and bring them to justice after so many years.

48 HOURS MYSTERY: "Postmarked for Murder" is produced by Mary Noonan Robichaux. Anthony Batson is the senior producer and Susan Zirinsky is the executive producer.